Move Python 2 libs to libs/py2

libs/py2/backports/__init__.py

@@ -0,0 +1 @@
+__path__ = __import__('pkgutil').extend_path(__path__, __name__)

libs/py2/backports/functools_lru_cache.py

@@ -0,0 +1,184 @@
+from __future__ import absolute_import
+
+import functools
+from collections import namedtuple
+from threading import RLock
+
+_CacheInfo = namedtuple("CacheInfo", ["hits", "misses", "maxsize", "currsize"])
+
+
+@functools.wraps(functools.update_wrapper)
+def update_wrapper(wrapper,
+                   wrapped,
+                   assigned = functools.WRAPPER_ASSIGNMENTS,
+                   updated = functools.WRAPPER_UPDATES):
+    """
+    Patch two bugs in functools.update_wrapper.
+    """
+    # workaround for http://bugs.python.org/issue3445
+    assigned = tuple(attr for attr in assigned if hasattr(wrapped, attr))
+    wrapper = functools.update_wrapper(wrapper, wrapped, assigned, updated)
+    # workaround for https://bugs.python.org/issue17482
+    wrapper.__wrapped__ = wrapped
+    return wrapper
+
+
+class _HashedSeq(list):
+    __slots__ = 'hashvalue'
+
+    def __init__(self, tup, hash=hash):
+        self[:] = tup
+        self.hashvalue = hash(tup)
+
+    def __hash__(self):
+        return self.hashvalue
+
+
+def _make_key(args, kwds, typed,
+              kwd_mark=(object(),),
+              fasttypes=set([int, str, frozenset, type(None)]),
+              sorted=sorted, tuple=tuple, type=type, len=len):
+    'Make a cache key from optionally typed positional and keyword arguments'
+    key = args
+    if kwds:
+        sorted_items = sorted(kwds.items())
+        key += kwd_mark
+        for item in sorted_items:
+            key += item
+    if typed:
+        key += tuple(type(v) for v in args)
+        if kwds:
+            key += tuple(type(v) for k, v in sorted_items)
+    elif len(key) == 1 and type(key[0]) in fasttypes:
+        return key[0]
+    return _HashedSeq(key)
+
+
+def lru_cache(maxsize=100, typed=False):
+    """Least-recently-used cache decorator.
+
+    If *maxsize* is set to None, the LRU features are disabled and the cache
+    can grow without bound.
+
+    If *typed* is True, arguments of different types will be cached separately.
+    For example, f(3.0) and f(3) will be treated as distinct calls with
+    distinct results.
+
+    Arguments to the cached function must be hashable.
+
+    View the cache statistics named tuple (hits, misses, maxsize, currsize) with
+    f.cache_info().  Clear the cache and statistics with f.cache_clear().
+    Access the underlying function with f.__wrapped__.
+
+    See:  http://en.wikipedia.org/wiki/Cache_algorithms#Least_Recently_Used
+
+    """
+
+    # Users should only access the lru_cache through its public API:
+    #       cache_info, cache_clear, and f.__wrapped__
+    # The internals of the lru_cache are encapsulated for thread safety and
+    # to allow the implementation to change (including a possible C version).
+
+    def decorating_function(user_function):
+
+        cache = dict()
+        stats = [0, 0]                  # make statistics updateable non-locally
+        HITS, MISSES = 0, 1             # names for the stats fields
+        make_key = _make_key
+        cache_get = cache.get           # bound method to lookup key or return None
+        _len = len                      # localize the global len() function
+        lock = RLock()                  # because linkedlist updates aren't threadsafe
+        root = []                       # root of the circular doubly linked list
+        root[:] = [root, root, None, None]      # initialize by pointing to self
+        nonlocal_root = [root]                  # make updateable non-locally
+        PREV, NEXT, KEY, RESULT = 0, 1, 2, 3    # names for the link fields
+
+        if maxsize == 0:
+
+            def wrapper(*args, **kwds):
+                # no caching, just do a statistics update after a successful call
+                result = user_function(*args, **kwds)
+                stats[MISSES] += 1
+                return result
+
+        elif maxsize is None:
+
+            def wrapper(*args, **kwds):
+                # simple caching without ordering or size limit
+                key = make_key(args, kwds, typed)
+                result = cache_get(key, root)   # root used here as a unique not-found sentinel
+                if result is not root:
+                    stats[HITS] += 1
+                    return result
+                result = user_function(*args, **kwds)
+                cache[key] = result
+                stats[MISSES] += 1
+                return result
+
+        else:
+
+            def wrapper(*args, **kwds):
+                # size limited caching that tracks accesses by recency
+                key = make_key(args, kwds, typed) if kwds or typed else args
+                with lock:
+                    link = cache_get(key)
+                    if link is not None:
+                        # record recent use of the key by moving it to the front of the list
+                        root, = nonlocal_root
+                        link_prev, link_next, key, result = link
+                        link_prev[NEXT] = link_next
+                        link_next[PREV] = link_prev
+                        last = root[PREV]
+                        last[NEXT] = root[PREV] = link
+                        link[PREV] = last
+                        link[NEXT] = root
+                        stats[HITS] += 1
+                        return result
+                result = user_function(*args, **kwds)
+                with lock:
+                    root, = nonlocal_root
+                    if key in cache:
+                        # getting here means that this same key was added to the
+                        # cache while the lock was released.  since the link
+                        # update is already done, we need only return the
+                        # computed result and update the count of misses.
+                        pass
+                    elif _len(cache) >= maxsize:
+                        # use the old root to store the new key and result
+                        oldroot = root
+                        oldroot[KEY] = key
+                        oldroot[RESULT] = result
+                        # empty the oldest link and make it the new root
+                        root = nonlocal_root[0] = oldroot[NEXT]
+                        oldkey = root[KEY]
+                        root[KEY] = root[RESULT] = None
+                        # now update the cache dictionary for the new links
+                        del cache[oldkey]
+                        cache[key] = oldroot
+                    else:
+                        # put result in a new link at the front of the list
+                        last = root[PREV]
+                        link = [last, root, key, result]
+                        last[NEXT] = root[PREV] = cache[key] = link
+                    stats[MISSES] += 1
+                return result
+
+        def cache_info():
+            """Report cache statistics"""
+            with lock:
+                return _CacheInfo(stats[HITS], stats[MISSES], maxsize, len(cache))
+
+        def cache_clear():
+            """Clear the cache and cache statistics"""
+            with lock:
+                cache.clear()
+                root = nonlocal_root[0]
+                root[:] = [root, root, None, None]
+                stats[:] = [0, 0]
+
+        wrapper.__wrapped__ = user_function
+        wrapper.cache_info = cache_info
+        wrapper.cache_clear = cache_clear
+        return update_wrapper(wrapper, user_function)
+
+    return decorating_function

libs/py2/concurrent/__init__.py

@@ -0,0 +1,3 @@
+from pkgutil import extend_path
+
+__path__ = extend_path(__path__, __name__)

libs/py2/concurrent/futures/__init__.py

@@ -0,0 +1,23 @@
+# Copyright 2009 Brian Quinlan. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Execute computations asynchronously using threads or processes."""
+
+__author__ = 'Brian Quinlan (brian@sweetapp.com)'
+
+from concurrent.futures._base import (FIRST_COMPLETED,
+                                      FIRST_EXCEPTION,
+                                      ALL_COMPLETED,
+                                      CancelledError,
+                                      TimeoutError,
+                                      Future,
+                                      Executor,
+                                      wait,
+                                      as_completed)
+from concurrent.futures.thread import ThreadPoolExecutor
+
+try:
+    from concurrent.futures.process import ProcessPoolExecutor
+except ImportError:
+    # some platforms don't have multiprocessing
+    pass

libs/py2/concurrent/futures/_base.py

@@ -0,0 +1,667 @@
+# Copyright 2009 Brian Quinlan. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+import collections
+import logging
+import threading
+import itertools
+import time
+import types
+
+__author__ = 'Brian Quinlan (brian@sweetapp.com)'
+
+FIRST_COMPLETED = 'FIRST_COMPLETED'
+FIRST_EXCEPTION = 'FIRST_EXCEPTION'
+ALL_COMPLETED = 'ALL_COMPLETED'
+_AS_COMPLETED = '_AS_COMPLETED'
+
+# Possible future states (for internal use by the futures package).
+PENDING = 'PENDING'
+RUNNING = 'RUNNING'
+# The future was cancelled by the user...
+CANCELLED = 'CANCELLED'
+# ...and _Waiter.add_cancelled() was called by a worker.
+CANCELLED_AND_NOTIFIED = 'CANCELLED_AND_NOTIFIED'
+FINISHED = 'FINISHED'
+
+_FUTURE_STATES = [
+    PENDING,
+    RUNNING,
+    CANCELLED,
+    CANCELLED_AND_NOTIFIED,
+    FINISHED
+]
+
+_STATE_TO_DESCRIPTION_MAP = {
+    PENDING: "pending",
+    RUNNING: "running",
+    CANCELLED: "cancelled",
+    CANCELLED_AND_NOTIFIED: "cancelled",
+    FINISHED: "finished"
+}
+
+# Logger for internal use by the futures package.
+LOGGER = logging.getLogger("concurrent.futures")
+
+class Error(Exception):
+    """Base class for all future-related exceptions."""
+    pass
+
+class CancelledError(Error):
+    """The Future was cancelled."""
+    pass
+
+class TimeoutError(Error):
+    """The operation exceeded the given deadline."""
+    pass
+
+class _Waiter(object):
+    """Provides the event that wait() and as_completed() block on."""
+    def __init__(self):
+        self.event = threading.Event()
+        self.finished_futures = []
+
+    def add_result(self, future):
+        self.finished_futures.append(future)
+
+    def add_exception(self, future):
+        self.finished_futures.append(future)
+
+    def add_cancelled(self, future):
+        self.finished_futures.append(future)
+
+class _AsCompletedWaiter(_Waiter):
+    """Used by as_completed()."""
+
+    def __init__(self):
+        super(_AsCompletedWaiter, self).__init__()
+        self.lock = threading.Lock()
+
+    def add_result(self, future):
+        with self.lock:
+            super(_AsCompletedWaiter, self).add_result(future)
+            self.event.set()
+
+    def add_exception(self, future):
+        with self.lock:
+            super(_AsCompletedWaiter, self).add_exception(future)
+            self.event.set()
+
+    def add_cancelled(self, future):
+        with self.lock:
+            super(_AsCompletedWaiter, self).add_cancelled(future)
+            self.event.set()
+
+class _FirstCompletedWaiter(_Waiter):
+    """Used by wait(return_when=FIRST_COMPLETED)."""
+
+    def add_result(self, future):
+        super(_FirstCompletedWaiter, self).add_result(future)
+        self.event.set()
+
+    def add_exception(self, future):
+        super(_FirstCompletedWaiter, self).add_exception(future)
+        self.event.set()
+
+    def add_cancelled(self, future):
+        super(_FirstCompletedWaiter, self).add_cancelled(future)
+        self.event.set()
+
+class _AllCompletedWaiter(_Waiter):
+    """Used by wait(return_when=FIRST_EXCEPTION and ALL_COMPLETED)."""
+
+    def __init__(self, num_pending_calls, stop_on_exception):
+        self.num_pending_calls = num_pending_calls
+        self.stop_on_exception = stop_on_exception
+        self.lock = threading.Lock()
+        super(_AllCompletedWaiter, self).__init__()
+
+    def _decrement_pending_calls(self):
+        with self.lock:
+            self.num_pending_calls -= 1
+            if not self.num_pending_calls:
+                self.event.set()
+
+    def add_result(self, future):
+        super(_AllCompletedWaiter, self).add_result(future)
+        self._decrement_pending_calls()
+
+    def add_exception(self, future):
+        super(_AllCompletedWaiter, self).add_exception(future)
+        if self.stop_on_exception:
+            self.event.set()
+        else:
+            self._decrement_pending_calls()
+
+    def add_cancelled(self, future):
+        super(_AllCompletedWaiter, self).add_cancelled(future)
+        self._decrement_pending_calls()
+
+class _AcquireFutures(object):
+    """A context manager that does an ordered acquire of Future conditions."""
+
+    def __init__(self, futures):
+        self.futures = sorted(futures, key=id)
+
+    def __enter__(self):
+        for future in self.futures:
+            future._condition.acquire()
+
+    def __exit__(self, *args):
+        for future in self.futures:
+            future._condition.release()
+
+def _create_and_install_waiters(fs, return_when):
+    if return_when == _AS_COMPLETED:
+        waiter = _AsCompletedWaiter()
+    elif return_when == FIRST_COMPLETED:
+        waiter = _FirstCompletedWaiter()
+    else:
+        pending_count = sum(
+                f._state not in [CANCELLED_AND_NOTIFIED, FINISHED] for f in fs)
+
+        if return_when == FIRST_EXCEPTION:
+            waiter = _AllCompletedWaiter(pending_count, stop_on_exception=True)
+        elif return_when == ALL_COMPLETED:
+            waiter = _AllCompletedWaiter(pending_count, stop_on_exception=False)
+        else:
+            raise ValueError("Invalid return condition: %r" % return_when)
+
+    for f in fs:
+        f._waiters.append(waiter)
+
+    return waiter
+
+
+def _yield_finished_futures(fs, waiter, ref_collect):
+    """
+    Iterate on the list *fs*, yielding finished futures one by one in
+    reverse order.
+    Before yielding a future, *waiter* is removed from its waiters
+    and the future is removed from each set in the collection of sets
+    *ref_collect*.
+
+    The aim of this function is to avoid keeping stale references after
+    the future is yielded and before the iterator resumes.
+    """
+    while fs:
+        f = fs[-1]
+        for futures_set in ref_collect:
+            futures_set.remove(f)
+        with f._condition:
+            f._waiters.remove(waiter)
+        del f
+        # Careful not to keep a reference to the popped value
+        yield fs.pop()
+
+
+def as_completed(fs, timeout=None):
+    """An iterator over the given futures that yields each as it completes.
+
+    Args:
+        fs: The sequence of Futures (possibly created by different Executors) to
+            iterate over.
+        timeout: The maximum number of seconds to wait. If None, then there
+            is no limit on the wait time.
+
+    Returns:
+        An iterator that yields the given Futures as they complete (finished or
+        cancelled). If any given Futures are duplicated, they will be returned
+        once.
+
+    Raises:
+        TimeoutError: If the entire result iterator could not be generated
+            before the given timeout.
+    """
+    if timeout is not None:
+        end_time = timeout + time.time()
+
+    fs = set(fs)
+    total_futures = len(fs)
+    with _AcquireFutures(fs):
+        finished = set(
+                f for f in fs
+                if f._state in [CANCELLED_AND_NOTIFIED, FINISHED])
+        pending = fs - finished
+        waiter = _create_and_install_waiters(fs, _AS_COMPLETED)
+    finished = list(finished)
+    try:
+        for f in _yield_finished_futures(finished, waiter,
+                                         ref_collect=(fs,)):
+            f = [f]
+            yield f.pop()
+
+        while pending:
+            if timeout is None:
+                wait_timeout = None
+            else:
+                wait_timeout = end_time - time.time()
+                if wait_timeout < 0:
+                    raise TimeoutError(
+                            '%d (of %d) futures unfinished' % (
+                            len(pending), total_futures))
+
+            waiter.event.wait(wait_timeout)
+
+            with waiter.lock:
+                finished = waiter.finished_futures
+                waiter.finished_futures = []
+                waiter.event.clear()
+
+            # reverse to keep finishing order
+            finished.reverse()
+            for f in _yield_finished_futures(finished, waiter,
+                                             ref_collect=(fs, pending)):
+                f = [f]
+                yield f.pop()
+
+    finally:
+        # Remove waiter from unfinished futures
+        for f in fs:
+            with f._condition:
+                f._waiters.remove(waiter)
+
+DoneAndNotDoneFutures = collections.namedtuple(
+        'DoneAndNotDoneFutures', 'done not_done')
+def wait(fs, timeout=None, return_when=ALL_COMPLETED):
+    """Wait for the futures in the given sequence to complete.
+
+    Args:
+        fs: The sequence of Futures (possibly created by different Executors) to
+            wait upon.
+        timeout: The maximum number of seconds to wait. If None, then there
+            is no limit on the wait time.
+        return_when: Indicates when this function should return. The options
+            are:
+
+            FIRST_COMPLETED - Return when any future finishes or is
+                              cancelled.
+            FIRST_EXCEPTION - Return when any future finishes by raising an
+                              exception. If no future raises an exception
+                              then it is equivalent to ALL_COMPLETED.
+            ALL_COMPLETED -   Return when all futures finish or are cancelled.
+
+    Returns:
+        A named 2-tuple of sets. The first set, named 'done', contains the
+        futures that completed (is finished or cancelled) before the wait
+        completed. The second set, named 'not_done', contains uncompleted
+        futures.
+    """
+    with _AcquireFutures(fs):
+        done = set(f for f in fs
+                   if f._state in [CANCELLED_AND_NOTIFIED, FINISHED])
+        not_done = set(fs) - done
+
+        if (return_when == FIRST_COMPLETED) and done:
+            return DoneAndNotDoneFutures(done, not_done)
+        elif (return_when == FIRST_EXCEPTION) and done:
+            if any(f for f in done
+                   if not f.cancelled() and f.exception() is not None):
+                return DoneAndNotDoneFutures(done, not_done)
+
+        if len(done) == len(fs):
+            return DoneAndNotDoneFutures(done, not_done)
+
+        waiter = _create_and_install_waiters(fs, return_when)
+
+    waiter.event.wait(timeout)
+    for f in fs:
+        with f._condition:
+            f._waiters.remove(waiter)
+
+    done.update(waiter.finished_futures)
+    return DoneAndNotDoneFutures(done, set(fs) - done)
+
+class Future(object):
+    """Represents the result of an asynchronous computation."""
+
+    def __init__(self):
+        """Initializes the future. Should not be called by clients."""
+        self._condition = threading.Condition()
+        self._state = PENDING
+        self._result = None
+        self._exception = None
+        self._traceback = None
+        self._waiters = []
+        self._done_callbacks = []
+
+    def _invoke_callbacks(self):
+        for callback in self._done_callbacks:
+            try:
+                callback(self)
+            except Exception:
+                LOGGER.exception('exception calling callback for %r', self)
+            except BaseException:
+                # Explicitly let all other new-style exceptions through so
+                # that we can catch all old-style exceptions with a simple
+                # "except:" clause below.
+                #
+                # All old-style exception objects are instances of
+                # types.InstanceType, but "except types.InstanceType:" does
+                # not catch old-style exceptions for some reason.  Thus, the
+                # only way to catch all old-style exceptions without catching
+                # any new-style exceptions is to filter out the new-style
+                # exceptions, which all derive from BaseException.
+                raise
+            except:
+                # Because of the BaseException clause above, this handler only
+                # executes for old-style exception objects.
+                LOGGER.exception('exception calling callback for %r', self)
+
+    def __repr__(self):
+        with self._condition:
+            if self._state == FINISHED:
+                if self._exception:
+                    return '<%s at %#x state=%s raised %s>' % (
+                        self.__class__.__name__,
+                        id(self),
+                        _STATE_TO_DESCRIPTION_MAP[self._state],
+                        self._exception.__class__.__name__)
+                else:
+                    return '<%s at %#x state=%s returned %s>' % (
+                        self.__class__.__name__,
+                        id(self),
+                        _STATE_TO_DESCRIPTION_MAP[self._state],
+                        self._result.__class__.__name__)
+            return '<%s at %#x state=%s>' % (
+                    self.__class__.__name__,
+                    id(self),
+                   _STATE_TO_DESCRIPTION_MAP[self._state])
+
+    def cancel(self):
+        """Cancel the future if possible.
+
+        Returns True if the future was cancelled, False otherwise. A future
+        cannot be cancelled if it is running or has already completed.
+        """
+        with self._condition:
+            if self._state in [RUNNING, FINISHED]:
+                return False
+
+            if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
+                return True
+
+            self._state = CANCELLED
+            self._condition.notify_all()
+
+        self._invoke_callbacks()
+        return True
+
+    def cancelled(self):
+        """Return True if the future was cancelled."""
+        with self._condition:
+            return self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]
+
+    def running(self):
+        """Return True if the future is currently executing."""
+        with self._condition:
+            return self._state == RUNNING
+
+    def done(self):
+        """Return True of the future was cancelled or finished executing."""
+        with self._condition:
+            return self._state in [CANCELLED, CANCELLED_AND_NOTIFIED, FINISHED]
+
+    def __get_result(self):
+        if self._exception:
+            if isinstance(self._exception, types.InstanceType):
+                # The exception is an instance of an old-style class, which
+                # means type(self._exception) returns types.ClassType instead
+                # of the exception's actual class type.
+                exception_type = self._exception.__class__
+            else:
+                exception_type = type(self._exception)
+            raise exception_type, self._exception, self._traceback
+        else:
+            return self._result
+
+    def add_done_callback(self, fn):
+        """Attaches a callable that will be called when the future finishes.
+
+        Args:
+            fn: A callable that will be called with this future as its only
+                argument when the future completes or is cancelled. The callable
+                will always be called by a thread in the same process in which
+                it was added. If the future has already completed or been
+                cancelled then the callable will be called immediately. These
+                callables are called in the order that they were added.
+        """
+        with self._condition:
+            if self._state not in [CANCELLED, CANCELLED_AND_NOTIFIED, FINISHED]:
+                self._done_callbacks.append(fn)
+                return
+        fn(self)
+
+    def result(self, timeout=None):
+        """Return the result of the call that the future represents.
+
+        Args:
+            timeout: The number of seconds to wait for the result if the future
+                isn't done. If None, then there is no limit on the wait time.
+
+        Returns:
+            The result of the call that the future represents.
+
+        Raises:
+            CancelledError: If the future was cancelled.
+            TimeoutError: If the future didn't finish executing before the given
+                timeout.
+            Exception: If the call raised then that exception will be raised.
+        """
+        with self._condition:
+            if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
+                raise CancelledError()
+            elif self._state == FINISHED:
+                return self.__get_result()
+
+            self._condition.wait(timeout)
+
+            if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
+                raise CancelledError()
+            elif self._state == FINISHED:
+                return self.__get_result()
+            else:
+                raise TimeoutError()
+
+    def exception_info(self, timeout=None):
+        """Return a tuple of (exception, traceback) raised by the call that the
+        future represents.
+
+        Args:
+            timeout: The number of seconds to wait for the exception if the
+                future isn't done. If None, then there is no limit on the wait
+                time.
+
+        Returns:
+            The exception raised by the call that the future represents or None
+            if the call completed without raising.
+
+        Raises:
+            CancelledError: If the future was cancelled.
+            TimeoutError: If the future didn't finish executing before the given
+                timeout.
+        """
+        with self._condition:
+            if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
+                raise CancelledError()
+            elif self._state == FINISHED:
+                return self._exception, self._traceback
+
+            self._condition.wait(timeout)
+
+            if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
+                raise CancelledError()
+            elif self._state == FINISHED:
+                return self._exception, self._traceback
+            else:
+                raise TimeoutError()
+
+    def exception(self, timeout=None):
+        """Return the exception raised by the call that the future represents.
+
+        Args:
+            timeout: The number of seconds to wait for the exception if the
+                future isn't done. If None, then there is no limit on the wait
+                time.
+
+        Returns:
+            The exception raised by the call that the future represents or None
+            if the call completed without raising.
+
+        Raises:
+            CancelledError: If the future was cancelled.
+            TimeoutError: If the future didn't finish executing before the given
+                timeout.
+        """
+        return self.exception_info(timeout)[0]
+
+    # The following methods should only be used by Executors and in tests.
+    def set_running_or_notify_cancel(self):
+        """Mark the future as running or process any cancel notifications.
+
+        Should only be used by Executor implementations and unit tests.
+
+        If the future has been cancelled (cancel() was called and returned
+        True) then any threads waiting on the future completing (though calls
+        to as_completed() or wait()) are notified and False is returned.
+
+        If the future was not cancelled then it is put in the running state
+        (future calls to running() will return True) and True is returned.
+
+        This method should be called by Executor implementations before
+        executing the work associated with this future. If this method returns
+        False then the work should not be executed.
+
+        Returns:
+            False if the Future was cancelled, True otherwise.
+
+        Raises:
+            RuntimeError: if this method was already called or if set_result()
+                or set_exception() was called.
+        """
+        with self._condition:
+            if self._state == CANCELLED:
+                self._state = CANCELLED_AND_NOTIFIED
+                for waiter in self._waiters:
+                    waiter.add_cancelled(self)
+                # self._condition.notify_all() is not necessary because
+                # self.cancel() triggers a notification.
+                return False
+            elif self._state == PENDING:
+                self._state = RUNNING
+                return True
+            else:
+                LOGGER.critical('Future %s in unexpected state: %s',
+                                id(self),
+                                self._state)
+                raise RuntimeError('Future in unexpected state')
+
+    def set_result(self, result):
+        """Sets the return value of work associated with the future.
+
+        Should only be used by Executor implementations and unit tests.
+        """
+        with self._condition:
+            self._result = result
+            self._state = FINISHED
+            for waiter in self._waiters:
+                waiter.add_result(self)
+            self._condition.notify_all()
+        self._invoke_callbacks()
+
+    def set_exception_info(self, exception, traceback):
+        """Sets the result of the future as being the given exception
+        and traceback.
+
+        Should only be used by Executor implementations and unit tests.
+        """
+        with self._condition:
+            self._exception = exception
+            self._traceback = traceback
+            self._state = FINISHED
+            for waiter in self._waiters:
+                waiter.add_exception(self)
+            self._condition.notify_all()
+        self._invoke_callbacks()
+
+    def set_exception(self, exception):
+        """Sets the result of the future as being the given exception.
+
+        Should only be used by Executor implementations and unit tests.
+        """
+        self.set_exception_info(exception, None)
+
+class Executor(object):
+    """This is an abstract base class for concrete asynchronous executors."""
+
+    def submit(self, fn, *args, **kwargs):
+        """Submits a callable to be executed with the given arguments.
+
+        Schedules the callable to be executed as fn(*args, **kwargs) and returns
+        a Future instance representing the execution of the callable.
+
+        Returns:
+            A Future representing the given call.
+        """
+        raise NotImplementedError()
+
+    def map(self, fn, *iterables, **kwargs):
+        """Returns an iterator equivalent to map(fn, iter).
+
+        Args:
+            fn: A callable that will take as many arguments as there are
+                passed iterables.
+            timeout: The maximum number of seconds to wait. If None, then there
+                is no limit on the wait time.
+
+        Returns:
+            An iterator equivalent to: map(func, *iterables) but the calls may
+            be evaluated out-of-order.
+
+        Raises:
+            TimeoutError: If the entire result iterator could not be generated
+                before the given timeout.
+            Exception: If fn(*args) raises for any values.
+        """
+        timeout = kwargs.get('timeout')
+        if timeout is not None:
+            end_time = timeout + time.time()
+
+        fs = [self.submit(fn, *args) for args in itertools.izip(*iterables)]
+
+        # Yield must be hidden in closure so that the futures are submitted
+        # before the first iterator value is required.
+        def result_iterator():
+            try:
+                # reverse to keep finishing order
+                fs.reverse()
+                while fs:
+                    # Careful not to keep a reference to the popped future
+                    if timeout is None:
+                        yield fs.pop().result()
+                    else:
+                        yield fs.pop().result(end_time - time.time())
+            finally:
+                for future in fs:
+                    future.cancel()
+        return result_iterator()
+
+    def shutdown(self, wait=True):
+        """Clean-up the resources associated with the Executor.
+
+        It is safe to call this method several times. Otherwise, no other
+        methods can be called after this one.
+
+        Args:
+            wait: If True then shutdown will not return until all running
+                futures have finished executing and the resources used by the
+                executor have been reclaimed.
+        """
+        pass
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.shutdown(wait=True)
+        return False

libs/py2/concurrent/futures/process.py

@@ -0,0 +1,363 @@
+# Copyright 2009 Brian Quinlan. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Implements ProcessPoolExecutor.
+
+The follow diagram and text describe the data-flow through the system:
+
+|======================= In-process =====================|== Out-of-process ==|
+
++----------+     +----------+       +--------+     +-----------+    +---------+
+|          |  => | Work Ids |    => |        |  => | Call Q    | => |         |
+|          |     +----------+       |        |     +-----------+    |         |
+|          |     | ...      |       |        |     | ...       |    |         |
+|          |     | 6        |       |        |     | 5, call() |    |         |
+|          |     | 7        |       |        |     | ...       |    |         |
+| Process  |     | ...      |       | Local  |     +-----------+    | Process |
+|  Pool    |     +----------+       | Worker |                      |  #1..n  |
+| Executor |                        | Thread |                      |         |
+|          |     +----------- +     |        |     +-----------+    |         |
+|          | <=> | Work Items | <=> |        | <=  | Result Q  | <= |         |
+|          |     +------------+     |        |     +-----------+    |         |
+|          |     | 6: call()  |     |        |     | ...       |    |         |
+|          |     |    future  |     |        |     | 4, result |    |         |
+|          |     | ...        |     |        |     | 3, except |    |         |
++----------+     +------------+     +--------+     +-----------+    +---------+
+
+Executor.submit() called:
+- creates a uniquely numbered _WorkItem and adds it to the "Work Items" dict
+- adds the id of the _WorkItem to the "Work Ids" queue
+
+Local worker thread:
+- reads work ids from the "Work Ids" queue and looks up the corresponding
+  WorkItem from the "Work Items" dict: if the work item has been cancelled then
+  it is simply removed from the dict, otherwise it is repackaged as a
+  _CallItem and put in the "Call Q". New _CallItems are put in the "Call Q"
+  until "Call Q" is full. NOTE: the size of the "Call Q" is kept small because
+  calls placed in the "Call Q" can no longer be cancelled with Future.cancel().
+- reads _ResultItems from "Result Q", updates the future stored in the
+  "Work Items" dict and deletes the dict entry
+
+Process #1..n:
+- reads _CallItems from "Call Q", executes the calls, and puts the resulting
+  _ResultItems in "Request Q"
+"""
+
+import atexit
+from concurrent.futures import _base
+import Queue as queue
+import multiprocessing
+import threading
+import weakref
+import sys
+
+__author__ = 'Brian Quinlan (brian@sweetapp.com)'
+
+# Workers are created as daemon threads and processes. This is done to allow the
+# interpreter to exit when there are still idle processes in a
+# ProcessPoolExecutor's process pool (i.e. shutdown() was not called). However,
+# allowing workers to die with the interpreter has two undesirable properties:
+#   - The workers would still be running during interpretor shutdown,
+#     meaning that they would fail in unpredictable ways.
+#   - The workers could be killed while evaluating a work item, which could
+#     be bad if the callable being evaluated has external side-effects e.g.
+#     writing to a file.
+#
+# To work around this problem, an exit handler is installed which tells the
+# workers to exit when their work queues are empty and then waits until the
+# threads/processes finish.
+
+_threads_queues = weakref.WeakKeyDictionary()
+_shutdown = False
+
+def _python_exit():
+    global _shutdown
+    _shutdown = True
+    items = list(_threads_queues.items()) if _threads_queues else ()
+    for t, q in items:
+        q.put(None)
+    for t, q in items:
+        t.join(sys.maxint)
+
+# Controls how many more calls than processes will be queued in the call queue.
+# A smaller number will mean that processes spend more time idle waiting for
+# work while a larger number will make Future.cancel() succeed less frequently
+# (Futures in the call queue cannot be cancelled).
+EXTRA_QUEUED_CALLS = 1
+
+class _WorkItem(object):
+    def __init__(self, future, fn, args, kwargs):
+        self.future = future
+        self.fn = fn
+        self.args = args
+        self.kwargs = kwargs
+
+class _ResultItem(object):
+    def __init__(self, work_id, exception=None, result=None):
+        self.work_id = work_id
+        self.exception = exception
+        self.result = result
+
+class _CallItem(object):
+    def __init__(self, work_id, fn, args, kwargs):
+        self.work_id = work_id
+        self.fn = fn
+        self.args = args
+        self.kwargs = kwargs
+
+def _process_worker(call_queue, result_queue):
+    """Evaluates calls from call_queue and places the results in result_queue.
+
+    This worker is run in a separate process.
+
+    Args:
+        call_queue: A multiprocessing.Queue of _CallItems that will be read and
+            evaluated by the worker.
+        result_queue: A multiprocessing.Queue of _ResultItems that will written
+            to by the worker.
+        shutdown: A multiprocessing.Event that will be set as a signal to the
+            worker that it should exit when call_queue is empty.
+    """
+    while True:
+        call_item = call_queue.get(block=True)
+        if call_item is None:
+            # Wake up queue management thread
+            result_queue.put(None)
+            return
+        try:
+            r = call_item.fn(*call_item.args, **call_item.kwargs)
+        except:
+            e = sys.exc_info()[1]
+            result_queue.put(_ResultItem(call_item.work_id,
+                                         exception=e))
+        else:
+            result_queue.put(_ResultItem(call_item.work_id,
+                                         result=r))
+
+def _add_call_item_to_queue(pending_work_items,
+                            work_ids,
+                            call_queue):
+    """Fills call_queue with _WorkItems from pending_work_items.
+
+    This function never blocks.
+
+    Args:
+        pending_work_items: A dict mapping work ids to _WorkItems e.g.
+            {5: <_WorkItem...>, 6: <_WorkItem...>, ...}
+        work_ids: A queue.Queue of work ids e.g. Queue([5, 6, ...]). Work ids
+            are consumed and the corresponding _WorkItems from
+            pending_work_items are transformed into _CallItems and put in
+            call_queue.
+        call_queue: A multiprocessing.Queue that will be filled with _CallItems
+            derived from _WorkItems.
+    """
+    while True:
+        if call_queue.full():
+            return
+        try:
+            work_id = work_ids.get(block=False)
+        except queue.Empty:
+            return
+        else:
+            work_item = pending_work_items[work_id]
+
+            if work_item.future.set_running_or_notify_cancel():
+                call_queue.put(_CallItem(work_id,
+                                         work_item.fn,
+                                         work_item.args,
+                                         work_item.kwargs),
+                               block=True)
+            else:
+                del pending_work_items[work_id]
+                continue
+
+def _queue_management_worker(executor_reference,
+                             processes,
+                             pending_work_items,
+                             work_ids_queue,
+                             call_queue,
+                             result_queue):
+    """Manages the communication between this process and the worker processes.
+
+    This function is run in a local thread.
+
+    Args:
+        executor_reference: A weakref.ref to the ProcessPoolExecutor that owns
+            this thread. Used to determine if the ProcessPoolExecutor has been
+            garbage collected and that this function can exit.
+        process: A list of the multiprocessing.Process instances used as
+            workers.
+        pending_work_items: A dict mapping work ids to _WorkItems e.g.
+            {5: <_WorkItem...>, 6: <_WorkItem...>, ...}
+        work_ids_queue: A queue.Queue of work ids e.g. Queue([5, 6, ...]).
+        call_queue: A multiprocessing.Queue that will be filled with _CallItems
+            derived from _WorkItems for processing by the process workers.
+        result_queue: A multiprocessing.Queue of _ResultItems generated by the
+            process workers.
+    """
+    nb_shutdown_processes = [0]
+    def shutdown_one_process():
+        """Tell a worker to terminate, which will in turn wake us again"""
+        call_queue.put(None)
+        nb_shutdown_processes[0] += 1
+    while True:
+        _add_call_item_to_queue(pending_work_items,
+                                work_ids_queue,
+                                call_queue)
+
+        result_item = result_queue.get(block=True)
+        if result_item is not None:
+            work_item = pending_work_items[result_item.work_id]
+            del pending_work_items[result_item.work_id]
+
+            if result_item.exception:
+                work_item.future.set_exception(result_item.exception)
+            else:
+                work_item.future.set_result(result_item.result)
+            # Delete references to object. See issue16284
+            del work_item
+        # Check whether we should start shutting down.
+        executor = executor_reference()
+        # No more work items can be added if:
+        #   - The interpreter is shutting down OR
+        #   - The executor that owns this worker has been collected OR
+        #   - The executor that owns this worker has been shutdown.
+        if _shutdown or executor is None or executor._shutdown_thread:
+            # Since no new work items can be added, it is safe to shutdown
+            # this thread if there are no pending work items.
+            if not pending_work_items:
+                while nb_shutdown_processes[0] < len(processes):
+                    shutdown_one_process()
+                # If .join() is not called on the created processes then
+                # some multiprocessing.Queue methods may deadlock on Mac OS
+                # X.
+                for p in processes:
+                    p.join()
+                call_queue.close()
+                return
+        del executor
+
+_system_limits_checked = False
+_system_limited = None
+def _check_system_limits():
+    global _system_limits_checked, _system_limited
+    if _system_limits_checked:
+        if _system_limited:
+            raise NotImplementedError(_system_limited)
+    _system_limits_checked = True
+    try:
+        import os
+        nsems_max = os.sysconf("SC_SEM_NSEMS_MAX")
+    except (AttributeError, ValueError):
+        # sysconf not available or setting not available
+        return
+    if nsems_max == -1:
+        # indetermine limit, assume that limit is determined
+        # by available memory only
+        return
+    if nsems_max >= 256:
+        # minimum number of semaphores available
+        # according to POSIX
+        return
+    _system_limited = "system provides too few semaphores (%d available, 256 necessary)" % nsems_max
+    raise NotImplementedError(_system_limited)
+
+
+class ProcessPoolExecutor(_base.Executor):
+    def __init__(self, max_workers=None):
+        """Initializes a new ProcessPoolExecutor instance.
+
+        Args:
+            max_workers: The maximum number of processes that can be used to
+                execute the given calls. If None or not given then as many
+                worker processes will be created as the machine has processors.
+        """
+        _check_system_limits()
+
+        if max_workers is None:
+            self._max_workers = multiprocessing.cpu_count()
+        else:
+            if max_workers <= 0:
+                raise ValueError("max_workers must be greater than 0")
+
+            self._max_workers = max_workers
+
+        # Make the call queue slightly larger than the number of processes to
+        # prevent the worker processes from idling. But don't make it too big
+        # because futures in the call queue cannot be cancelled.
+        self._call_queue = multiprocessing.Queue(self._max_workers +
+                                                 EXTRA_QUEUED_CALLS)
+        self._result_queue = multiprocessing.Queue()
+        self._work_ids = queue.Queue()
+        self._queue_management_thread = None
+        self._processes = set()
+
+        # Shutdown is a two-step process.
+        self._shutdown_thread = False
+        self._shutdown_lock = threading.Lock()
+        self._queue_count = 0
+        self._pending_work_items = {}
+
+    def _start_queue_management_thread(self):
+        # When the executor gets lost, the weakref callback will wake up
+        # the queue management thread.
+        def weakref_cb(_, q=self._result_queue):
+            q.put(None)
+        if self._queue_management_thread is None:
+            self._queue_management_thread = threading.Thread(
+                    target=_queue_management_worker,
+                    args=(weakref.ref(self, weakref_cb),
+                          self._processes,
+                          self._pending_work_items,
+                          self._work_ids,
+                          self._call_queue,
+                          self._result_queue))
+            self._queue_management_thread.daemon = True
+            self._queue_management_thread.start()
+            _threads_queues[self._queue_management_thread] = self._result_queue
+
+    def _adjust_process_count(self):
+        for _ in range(len(self._processes), self._max_workers):
+            p = multiprocessing.Process(
+                    target=_process_worker,
+                    args=(self._call_queue,
+                          self._result_queue))
+            p.start()
+            self._processes.add(p)
+
+    def submit(self, fn, *args, **kwargs):
+        with self._shutdown_lock:
+            if self._shutdown_thread:
+                raise RuntimeError('cannot schedule new futures after shutdown')
+
+            f = _base.Future()
+            w = _WorkItem(f, fn, args, kwargs)
+
+            self._pending_work_items[self._queue_count] = w
+            self._work_ids.put(self._queue_count)
+            self._queue_count += 1
+            # Wake up queue management thread
+            self._result_queue.put(None)
+
+            self._start_queue_management_thread()
+            self._adjust_process_count()
+            return f
+    submit.__doc__ = _base.Executor.submit.__doc__
+
+    def shutdown(self, wait=True):
+        with self._shutdown_lock:
+            self._shutdown_thread = True
+        if self._queue_management_thread:
+            # Wake up queue management thread
+            self._result_queue.put(None)
+            if wait:
+                self._queue_management_thread.join(sys.maxint)
+        # To reduce the risk of openning too many files, remove references to
+        # objects that use file descriptors.
+        self._queue_management_thread = None
+        self._call_queue = None
+        self._result_queue = None
+        self._processes = None
+    shutdown.__doc__ = _base.Executor.shutdown.__doc__
+
+atexit.register(_python_exit)

libs/py2/concurrent/futures/thread.py

@@ -0,0 +1,160 @@
+# Copyright 2009 Brian Quinlan. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Implements ThreadPoolExecutor."""
+
+import atexit
+from concurrent.futures import _base
+import itertools
+import Queue as queue
+import threading
+import weakref
+import sys
+
+try:
+    from multiprocessing import cpu_count
+except ImportError:
+    # some platforms don't have multiprocessing
+    def cpu_count():
+        return None
+
+__author__ = 'Brian Quinlan (brian@sweetapp.com)'
+
+# Workers are created as daemon threads. This is done to allow the interpreter
+# to exit when there are still idle threads in a ThreadPoolExecutor's thread
+# pool (i.e. shutdown() was not called). However, allowing workers to die with
+# the interpreter has two undesirable properties:
+#   - The workers would still be running during interpretor shutdown,
+#     meaning that they would fail in unpredictable ways.
+#   - The workers could be killed while evaluating a work item, which could
+#     be bad if the callable being evaluated has external side-effects e.g.
+#     writing to a file.
+#
+# To work around this problem, an exit handler is installed which tells the
+# workers to exit when their work queues are empty and then waits until the
+# threads finish.
+
+_threads_queues = weakref.WeakKeyDictionary()
+_shutdown = False
+
+def _python_exit():
+    global _shutdown
+    _shutdown = True
+    items = list(_threads_queues.items()) if _threads_queues else ()
+    for t, q in items:
+        q.put(None)
+    for t, q in items:
+        t.join(sys.maxint)
+
+atexit.register(_python_exit)
+
+class _WorkItem(object):
+    def __init__(self, future, fn, args, kwargs):
+        self.future = future
+        self.fn = fn
+        self.args = args
+        self.kwargs = kwargs
+
+    def run(self):
+        if not self.future.set_running_or_notify_cancel():
+            return
+
+        try:
+            result = self.fn(*self.args, **self.kwargs)
+        except:
+            e, tb = sys.exc_info()[1:]
+            self.future.set_exception_info(e, tb)
+        else:
+            self.future.set_result(result)
+
+def _worker(executor_reference, work_queue):
+    try:
+        while True:
+            work_item = work_queue.get(block=True)
+            if work_item is not None:
+                work_item.run()
+                # Delete references to object. See issue16284
+                del work_item
+                continue
+            executor = executor_reference()
+            # Exit if:
+            #   - The interpreter is shutting down OR
+            #   - The executor that owns the worker has been collected OR
+            #   - The executor that owns the worker has been shutdown.
+            if _shutdown or executor is None or executor._shutdown:
+                # Notice other workers
+                work_queue.put(None)
+                return
+            del executor
+    except:
+        _base.LOGGER.critical('Exception in worker', exc_info=True)
+
+
+class ThreadPoolExecutor(_base.Executor):
+
+    # Used to assign unique thread names when thread_name_prefix is not supplied.
+    _counter = itertools.count().next
+
+    def __init__(self, max_workers=None, thread_name_prefix=''):
+        """Initializes a new ThreadPoolExecutor instance.
+
+        Args:
+            max_workers: The maximum number of threads that can be used to
+                execute the given calls.
+            thread_name_prefix: An optional name prefix to give our threads.
+        """
+        if max_workers is None:
+            # Use this number because ThreadPoolExecutor is often
+            # used to overlap I/O instead of CPU work.
+            max_workers = (cpu_count() or 1) * 5
+        if max_workers <= 0:
+            raise ValueError("max_workers must be greater than 0")
+
+        self._max_workers = max_workers
+        self._work_queue = queue.Queue()
+        self._threads = set()
+        self._shutdown = False
+        self._shutdown_lock = threading.Lock()
+        self._thread_name_prefix = (thread_name_prefix or
+                                    ("ThreadPoolExecutor-%d" % self._counter()))
+
+    def submit(self, fn, *args, **kwargs):
+        with self._shutdown_lock:
+            if self._shutdown:
+                raise RuntimeError('cannot schedule new futures after shutdown')
+
+            f = _base.Future()
+            w = _WorkItem(f, fn, args, kwargs)
+
+            self._work_queue.put(w)
+            self._adjust_thread_count()
+            return f
+    submit.__doc__ = _base.Executor.submit.__doc__
+
+    def _adjust_thread_count(self):
+        # When the executor gets lost, the weakref callback will wake up
+        # the worker threads.
+        def weakref_cb(_, q=self._work_queue):
+            q.put(None)
+        # TODO(bquinlan): Should avoid creating new threads if there are more
+        # idle threads than items in the work queue.
+        num_threads = len(self._threads)
+        if num_threads < self._max_workers:
+            thread_name = '%s_%d' % (self._thread_name_prefix or self,
+                                     num_threads)
+            t = threading.Thread(name=thread_name, target=_worker,
+                                 args=(weakref.ref(self, weakref_cb),
+                                       self._work_queue))
+            t.daemon = True
+            t.start()
+            self._threads.add(t)
+            _threads_queues[t] = self._work_queue
+
+    def shutdown(self, wait=True):
+        with self._shutdown_lock:
+            self._shutdown = True
+            self._work_queue.put(None)
+        if wait:
+            for t in self._threads:
+                t.join(sys.maxint)
+    shutdown.__doc__ = _base.Executor.shutdown.__doc__

libs/py2/enum/LICENSE

@@ -0,0 +1,32 @@
+Copyright (c) 2013, Ethan Furman.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    Redistributions of source code must retain the above
+    copyright notice, this list of conditions and the
+    following disclaimer.
+
+    Redistributions in binary form must reproduce the above
+    copyright notice, this list of conditions and the following
+    disclaimer in the documentation and/or other materials
+    provided with the distribution.
+
+    Neither the name Ethan Furman nor the names of any
+    contributors may be used to endorse or promote products
+    derived from this software without specific prior written
+    permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.

libs/py2/enum/README

@@ -0,0 +1,3 @@
+enum34 is the new Python stdlib enum module available in Python 3.4
+backported for previous versions of Python from 2.4 to 3.3.
+tested on 2.6, 2.7, and 3.3+

libs/py2/enum/__init__.py

@@ -0,0 +1,837 @@
+"""Python Enumerations"""
+
+import sys as _sys
+
+__all__ = ['Enum', 'IntEnum', 'unique']
+
+version = 1, 1, 6
+
+pyver = float('%s.%s' % _sys.version_info[:2])
+
+try:
+    any
+except NameError:
+    def any(iterable):
+        for element in iterable:
+            if element:
+                return True
+        return False
+
+try:
+    from collections import OrderedDict
+except ImportError:
+    OrderedDict = None
+
+try:
+    basestring
+except NameError:
+    # In Python 2 basestring is the ancestor of both str and unicode
+    # in Python 3 it's just str, but was missing in 3.1
+    basestring = str
+
+try:
+    unicode
+except NameError:
+    # In Python 3 unicode no longer exists (it's just str)
+    unicode = str
+
+class _RouteClassAttributeToGetattr(object):
+    """Route attribute access on a class to __getattr__.
+
+    This is a descriptor, used to define attributes that act differently when
+    accessed through an instance and through a class.  Instance access remains
+    normal, but access to an attribute through a class will be routed to the
+    class's __getattr__ method; this is done by raising AttributeError.
+
+    """
+    def __init__(self, fget=None):
+        self.fget = fget
+
+    def __get__(self, instance, ownerclass=None):
+        if instance is None:
+            raise AttributeError()
+        return self.fget(instance)
+
+    def __set__(self, instance, value):
+        raise AttributeError("can't set attribute")
+
+    def __delete__(self, instance):
+        raise AttributeError("can't delete attribute")
+
+
+def _is_descriptor(obj):
+    """Returns True if obj is a descriptor, False otherwise."""
+    return (
+            hasattr(obj, '__get__') or
+            hasattr(obj, '__set__') or
+            hasattr(obj, '__delete__'))
+
+
+def _is_dunder(name):
+    """Returns True if a __dunder__ name, False otherwise."""
+    return (name[:2] == name[-2:] == '__' and
+            name[2:3] != '_' and
+            name[-3:-2] != '_' and
+            len(name) > 4)
+
+
+def _is_sunder(name):
+    """Returns True if a _sunder_ name, False otherwise."""
+    return (name[0] == name[-1] == '_' and
+            name[1:2] != '_' and
+            name[-2:-1] != '_' and
+            len(name) > 2)
+
+
+def _make_class_unpicklable(cls):
+    """Make the given class un-picklable."""
+    def _break_on_call_reduce(self, protocol=None):
+        raise TypeError('%r cannot be pickled' % self)
+    cls.__reduce_ex__ = _break_on_call_reduce
+    cls.__module__ = '<unknown>'
+
+
+class _EnumDict(dict):
+    """Track enum member order and ensure member names are not reused.
+
+    EnumMeta will use the names found in self._member_names as the
+    enumeration member names.
+
+    """
+    def __init__(self):
+        super(_EnumDict, self).__init__()
+        self._member_names = []
+
+    def __setitem__(self, key, value):
+        """Changes anything not dundered or not a descriptor.
+
+        If a descriptor is added with the same name as an enum member, the name
+        is removed from _member_names (this may leave a hole in the numerical
+        sequence of values).
+
+        If an enum member name is used twice, an error is raised; duplicate
+        values are not checked for.
+
+        Single underscore (sunder) names are reserved.
+
+        Note:   in 3.x __order__ is simply discarded as a not necessary piece
+                leftover from 2.x
+
+        """
+        if pyver >= 3.0 and key in ('_order_', '__order__'):
+            return
+        elif key == '__order__':
+            key = '_order_'
+        if _is_sunder(key):
+            if key != '_order_':
+                raise ValueError('_names_ are reserved for future Enum use')
+        elif _is_dunder(key):
+            pass
+        elif key in self._member_names:
+            # descriptor overwriting an enum?
+            raise TypeError('Attempted to reuse key: %r' % key)
+        elif not _is_descriptor(value):
+            if key in self:
+                # enum overwriting a descriptor?
+                raise TypeError('Key already defined as: %r' % self[key])
+            self._member_names.append(key)
+        super(_EnumDict, self).__setitem__(key, value)
+
+
+# Dummy value for Enum as EnumMeta explicity checks for it, but of course until
+# EnumMeta finishes running the first time the Enum class doesn't exist.  This
+# is also why there are checks in EnumMeta like `if Enum is not None`
+Enum = None
+
+
+class EnumMeta(type):
+    """Metaclass for Enum"""
+    @classmethod
+    def __prepare__(metacls, cls, bases):
+        return _EnumDict()
+
+    def __new__(metacls, cls, bases, classdict):
+        # an Enum class is final once enumeration items have been defined; it
+        # cannot be mixed with other types (int, float, etc.) if it has an
+        # inherited __new__ unless a new __new__ is defined (or the resulting
+        # class will fail).
+        if type(classdict) is dict:
+            original_dict = classdict
+            classdict = _EnumDict()
+            for k, v in original_dict.items():
+                classdict[k] = v
+
+        member_type, first_enum = metacls._get_mixins_(bases)
+        __new__, save_new, use_args = metacls._find_new_(classdict, member_type,
+                                                        first_enum)
+        # save enum items into separate mapping so they don't get baked into
+        # the new class
+        members = dict((k, classdict[k]) for k in classdict._member_names)
+        for name in classdict._member_names:
+            del classdict[name]
+
+        # py2 support for definition order
+        _order_ = classdict.get('_order_')
+        if _order_ is None:
+            if pyver < 3.0:
+                try:
+                    _order_ = [name for (name, value) in sorted(members.items(), key=lambda item: item[1])]
+                except TypeError:
+                    _order_ = [name for name in sorted(members.keys())]
+            else:
+                _order_ = classdict._member_names
+        else:
+            del classdict['_order_']
+            if pyver < 3.0:
+                _order_ = _order_.replace(',', ' ').split()
+                aliases = [name for name in members if name not in _order_]
+                _order_ += aliases
+
+        # check for illegal enum names (any others?)
+        invalid_names = set(members) & set(['mro'])
+        if invalid_names:
+            raise ValueError('Invalid enum member name(s): %s' % (
+                ', '.join(invalid_names), ))
+
+        # save attributes from super classes so we know if we can take
+        # the shortcut of storing members in the class dict
+        base_attributes = set([a for b in bases for a in b.__dict__])
+        # create our new Enum type
+        enum_class = super(EnumMeta, metacls).__new__(metacls, cls, bases, classdict)
+        enum_class._member_names_ = []               # names in random order
+        if OrderedDict is not None:
+            enum_class._member_map_ = OrderedDict()
+        else:
+            enum_class._member_map_ = {}             # name->value map
+        enum_class._member_type_ = member_type
+
+        # Reverse value->name map for hashable values.
+        enum_class._value2member_map_ = {}
+
+        # instantiate them, checking for duplicates as we go
+        # we instantiate first instead of checking for duplicates first in case
+        # a custom __new__ is doing something funky with the values -- such as
+        # auto-numbering ;)
+        if __new__ is None:
+            __new__ = enum_class.__new__
+        for member_name in _order_:
+            value = members[member_name]
+            if not isinstance(value, tuple):
+                args = (value, )
+            else:
+                args = value
+            if member_type is tuple:   # special case for tuple enums
+                args = (args, )     # wrap it one more time
+            if not use_args or not args:
+                enum_member = __new__(enum_class)
+                if not hasattr(enum_member, '_value_'):
+                    enum_member._value_ = value
+            else:
+                enum_member = __new__(enum_class, *args)
+                if not hasattr(enum_member, '_value_'):
+                    enum_member._value_ = member_type(*args)
+            value = enum_member._value_
+            enum_member._name_ = member_name
+            enum_member.__objclass__ = enum_class
+            enum_member.__init__(*args)
+            # If another member with the same value was already defined, the
+            # new member becomes an alias to the existing one.
+            for name, canonical_member in enum_class._member_map_.items():
+                if canonical_member.value == enum_member._value_:
+                    enum_member = canonical_member
+                    break
+            else:
+                # Aliases don't appear in member names (only in __members__).
+                enum_class._member_names_.append(member_name)
+            # performance boost for any member that would not shadow
+            # a DynamicClassAttribute (aka _RouteClassAttributeToGetattr)
+            if member_name not in base_attributes:
+                setattr(enum_class, member_name, enum_member)
+            # now add to _member_map_
+            enum_class._member_map_[member_name] = enum_member
+            try:
+                # This may fail if value is not hashable. We can't add the value
+                # to the map, and by-value lookups for this value will be
+                # linear.
+                enum_class._value2member_map_[value] = enum_member
+            except TypeError:
+                pass
+
+
+        # If a custom type is mixed into the Enum, and it does not know how
+        # to pickle itself, pickle.dumps will succeed but pickle.loads will
+        # fail.  Rather than have the error show up later and possibly far
+        # from the source, sabotage the pickle protocol for this class so
+        # that pickle.dumps also fails.
+        #
+        # However, if the new class implements its own __reduce_ex__, do not
+        # sabotage -- it's on them to make sure it works correctly.  We use
+        # __reduce_ex__ instead of any of the others as it is preferred by
+        # pickle over __reduce__, and it handles all pickle protocols.
+        unpicklable = False
+        if '__reduce_ex__' not in classdict:
+            if member_type is not object:
+                methods = ('__getnewargs_ex__', '__getnewargs__',
+                        '__reduce_ex__', '__reduce__')
+                if not any(m in member_type.__dict__ for m in methods):
+                    _make_class_unpicklable(enum_class)
+                    unpicklable = True
+
+
+        # double check that repr and friends are not the mixin's or various
+        # things break (such as pickle)
+        for name in ('__repr__', '__str__', '__format__', '__reduce_ex__'):
+            class_method = getattr(enum_class, name)
+            obj_method = getattr(member_type, name, None)
+            enum_method = getattr(first_enum, name, None)
+            if name not in classdict and class_method is not enum_method:
+                if name == '__reduce_ex__' and unpicklable:
+                    continue
+                setattr(enum_class, name, enum_method)
+
+        # method resolution and int's are not playing nice
+        # Python's less than 2.6 use __cmp__
+
+        if pyver < 2.6:
+
+            if issubclass(enum_class, int):
+                setattr(enum_class, '__cmp__', getattr(int, '__cmp__'))
+
+        elif pyver < 3.0:
+
+            if issubclass(enum_class, int):
+                for method in (
+                        '__le__',
+                        '__lt__',
+                        '__gt__',
+                        '__ge__',
+                        '__eq__',
+                        '__ne__',
+                        '__hash__',
+                        ):
+                    setattr(enum_class, method, getattr(int, method))
+
+        # replace any other __new__ with our own (as long as Enum is not None,
+        # anyway) -- again, this is to support pickle
+        if Enum is not None:
+            # if the user defined their own __new__, save it before it gets
+            # clobbered in case they subclass later
+            if save_new:
+                setattr(enum_class, '__member_new__', enum_class.__dict__['__new__'])
+            setattr(enum_class, '__new__', Enum.__dict__['__new__'])
+        return enum_class
+
+    def __bool__(cls):
+        """
+        classes/types should always be True.
+        """
+        return True
+
+    def __call__(cls, value, names=None, module=None, type=None, start=1):
+        """Either returns an existing member, or creates a new enum class.
+
+        This method is used both when an enum class is given a value to match
+        to an enumeration member (i.e. Color(3)) and for the functional API
+        (i.e. Color = Enum('Color', names='red green blue')).
+
+        When used for the functional API: `module`, if set, will be stored in
+        the new class' __module__ attribute; `type`, if set, will be mixed in
+        as the first base class.
+
+        Note: if `module` is not set this routine will attempt to discover the
+        calling module by walking the frame stack; if this is unsuccessful
+        the resulting class will not be pickleable.
+
+        """
+        if names is None:  # simple value lookup
+            return cls.__new__(cls, value)
+        # otherwise, functional API: we're creating a new Enum type
+        return cls._create_(value, names, module=module, type=type, start=start)
+
+    def __contains__(cls, member):
+        return isinstance(member, cls) and member.name in cls._member_map_
+
+    def __delattr__(cls, attr):
+        # nicer error message when someone tries to delete an attribute
+        # (see issue19025).
+        if attr in cls._member_map_:
+            raise AttributeError(
+                    "%s: cannot delete Enum member." % cls.__name__)
+        super(EnumMeta, cls).__delattr__(attr)
+
+    def __dir__(self):
+        return (['__class__', '__doc__', '__members__', '__module__'] +
+                self._member_names_)
+
+    @property
+    def __members__(cls):
+        """Returns a mapping of member name->value.
+
+        This mapping lists all enum members, including aliases. Note that this
+        is a copy of the internal mapping.
+
+        """
+        return cls._member_map_.copy()
+
+    def __getattr__(cls, name):
+        """Return the enum member matching `name`
+
+        We use __getattr__ instead of descriptors or inserting into the enum
+        class' __dict__ in order to support `name` and `value` being both
+        properties for enum members (which live in the class' __dict__) and
+        enum members themselves.
+
+        """
+        if _is_dunder(name):
+            raise AttributeError(name)
+        try:
+            return cls._member_map_[name]
+        except KeyError:
+            raise AttributeError(name)
+
+    def __getitem__(cls, name):
+        return cls._member_map_[name]
+
+    def __iter__(cls):
+        return (cls._member_map_[name] for name in cls._member_names_)
+
+    def __reversed__(cls):
+        return (cls._member_map_[name] for name in reversed(cls._member_names_))
+
+    def __len__(cls):
+        return len(cls._member_names_)
+
+    __nonzero__ = __bool__
+
+    def __repr__(cls):
+        return "<enum %r>" % cls.__name__
+
+    def __setattr__(cls, name, value):
+        """Block attempts to reassign Enum members.
+
+        A simple assignment to the class namespace only changes one of the
+        several possible ways to get an Enum member from the Enum class,
+        resulting in an inconsistent Enumeration.
+
+        """
+        member_map = cls.__dict__.get('_member_map_', {})
+        if name in member_map:
+            raise AttributeError('Cannot reassign members.')
+        super(EnumMeta, cls).__setattr__(name, value)
+
+    def _create_(cls, class_name, names=None, module=None, type=None, start=1):
+        """Convenience method to create a new Enum class.
+
+        `names` can be:
+
+        * A string containing member names, separated either with spaces or
+          commas.  Values are auto-numbered from 1.
+        * An iterable of member names.  Values are auto-numbered from 1.
+        * An iterable of (member name, value) pairs.
+        * A mapping of member name -> value.
+
+        """
+        if pyver < 3.0:
+            # if class_name is unicode, attempt a conversion to ASCII
+            if isinstance(class_name, unicode):
+                try:
+                    class_name = class_name.encode('ascii')
+                except UnicodeEncodeError:
+                    raise TypeError('%r is not representable in ASCII' % class_name)
+        metacls = cls.__class__
+        if type is None:
+            bases = (cls, )
+        else:
+            bases = (type, cls)
+        classdict = metacls.__prepare__(class_name, bases)
+        _order_ = []
+
+        # special processing needed for names?
+        if isinstance(names, basestring):
+            names = names.replace(',', ' ').split()
+        if isinstance(names, (tuple, list)) and isinstance(names[0], basestring):
+            names = [(e, i+start) for (i, e) in enumerate(names)]
+
+        # Here, names is either an iterable of (name, value) or a mapping.
+        item = None  # in case names is empty
+        for item in names:
+            if isinstance(item, basestring):
+                member_name, member_value = item, names[item]
+            else:
+                member_name, member_value = item
+            classdict[member_name] = member_value
+            _order_.append(member_name)
+        # only set _order_ in classdict if name/value was not from a mapping
+        if not isinstance(item, basestring):
+            classdict['_order_'] = ' '.join(_order_)
+        enum_class = metacls.__new__(metacls, class_name, bases, classdict)
+
+        # TODO: replace the frame hack if a blessed way to know the calling
+        # module is ever developed
+        if module is None:
+            try:
+                module = _sys._getframe(2).f_globals['__name__']
+            except (AttributeError, ValueError):
+                pass
+        if module is None:
+            _make_class_unpicklable(enum_class)
+        else:
+            enum_class.__module__ = module
+
+        return enum_class
+
+    @staticmethod
+    def _get_mixins_(bases):
+        """Returns the type for creating enum members, and the first inherited
+        enum class.
+
+        bases: the tuple of bases that was given to __new__
+
+        """
+        if not bases or Enum is None:
+            return object, Enum
+
+
+        # double check that we are not subclassing a class with existing
+        # enumeration members; while we're at it, see if any other data
+        # type has been mixed in so we can use the correct __new__
+        member_type = first_enum = None
+        for base in bases:
+            if  (base is not Enum and
+                    issubclass(base, Enum) and
+                    base._member_names_):
+                raise TypeError("Cannot extend enumerations")
+        # base is now the last base in bases
+        if not issubclass(base, Enum):
+            raise TypeError("new enumerations must be created as "
+                    "`ClassName([mixin_type,] enum_type)`")
+
+        # get correct mix-in type (either mix-in type of Enum subclass, or
+        # first base if last base is Enum)
+        if not issubclass(bases[0], Enum):
+            member_type = bases[0]     # first data type
+            first_enum = bases[-1]  # enum type
+        else:
+            for base in bases[0].__mro__:
+                # most common: (IntEnum, int, Enum, object)
+                # possible:    (<Enum 'AutoIntEnum'>, <Enum 'IntEnum'>,
+                #               <class 'int'>, <Enum 'Enum'>,
+                #               <class 'object'>)
+                if issubclass(base, Enum):
+                    if first_enum is None:
+                        first_enum = base
+                else:
+                    if member_type is None:
+                        member_type = base
+
+        return member_type, first_enum
+
+    if pyver < 3.0:
+        @staticmethod
+        def _find_new_(classdict, member_type, first_enum):
+            """Returns the __new__ to be used for creating the enum members.
+
+            classdict: the class dictionary given to __new__
+            member_type: the data type whose __new__ will be used by default
+            first_enum: enumeration to check for an overriding __new__
+
+            """
+            # now find the correct __new__, checking to see of one was defined
+            # by the user; also check earlier enum classes in case a __new__ was
+            # saved as __member_new__
+            __new__ = classdict.get('__new__', None)
+            if __new__:
+                return None, True, True      # __new__, save_new, use_args
+
+            N__new__ = getattr(None, '__new__')
+            O__new__ = getattr(object, '__new__')
+            if Enum is None:
+                E__new__ = N__new__
+            else:
+                E__new__ = Enum.__dict__['__new__']
+            # check all possibles for __member_new__ before falling back to
+            # __new__
+            for method in ('__member_new__', '__new__'):
+                for possible in (member_type, first_enum):
+                    try:
+                        target = possible.__dict__[method]
+                    except (AttributeError, KeyError):
+                        target = getattr(possible, method, None)
+                    if target not in [
+                            None,
+                            N__new__,
+                            O__new__,
+                            E__new__,
+                            ]:
+                        if method == '__member_new__':
+                            classdict['__new__'] = target
+                            return None, False, True
+                        if isinstance(target, staticmethod):
+                            target = target.__get__(member_type)
+                        __new__ = target
+                        break
+                if __new__ is not None:
+                    break
+            else:
+                __new__ = object.__new__
+
+            # if a non-object.__new__ is used then whatever value/tuple was
+            # assigned to the enum member name will be passed to __new__ and to the
+            # new enum member's __init__
+            if __new__ is object.__new__:
+                use_args = False
+            else:
+                use_args = True
+
+            return __new__, False, use_args
+    else:
+        @staticmethod
+        def _find_new_(classdict, member_type, first_enum):
+            """Returns the __new__ to be used for creating the enum members.
+
+            classdict: the class dictionary given to __new__
+            member_type: the data type whose __new__ will be used by default
+            first_enum: enumeration to check for an overriding __new__
+
+            """
+            # now find the correct __new__, checking to see of one was defined
+            # by the user; also check earlier enum classes in case a __new__ was
+            # saved as __member_new__
+            __new__ = classdict.get('__new__', None)
+
+            # should __new__ be saved as __member_new__ later?
+            save_new = __new__ is not None
+
+            if __new__ is None:
+                # check all possibles for __member_new__ before falling back to
+                # __new__
+                for method in ('__member_new__', '__new__'):
+                    for possible in (member_type, first_enum):
+                        target = getattr(possible, method, None)
+                        if target not in (
+                                None,
+                                None.__new__,
+                                object.__new__,
+                                Enum.__new__,
+                                ):
+                            __new__ = target
+                            break
+                    if __new__ is not None:
+                        break
+                else:
+                    __new__ = object.__new__
+
+            # if a non-object.__new__ is used then whatever value/tuple was
+            # assigned to the enum member name will be passed to __new__ and to the
+            # new enum member's __init__
+            if __new__ is object.__new__:
+                use_args = False
+            else:
+                use_args = True
+
+            return __new__, save_new, use_args
+
+
+########################################################
+# In order to support Python 2 and 3 with a single
+# codebase we have to create the Enum methods separately
+# and then use the `type(name, bases, dict)` method to
+# create the class.
+########################################################
+temp_enum_dict = {}
+temp_enum_dict['__doc__'] = "Generic enumeration.\n\n    Derive from this class to define new enumerations.\n\n"
+
+def __new__(cls, value):
+    # all enum instances are actually created during class construction
+    # without calling this method; this method is called by the metaclass'
+    # __call__ (i.e. Color(3) ), and by pickle
+    if type(value) is cls:
+        # For lookups like Color(Color.red)
+        value = value.value
+        #return value
+    # by-value search for a matching enum member
+    # see if it's in the reverse mapping (for hashable values)
+    try:
+        if value in cls._value2member_map_:
+            return cls._value2member_map_[value]
+    except TypeError:
+        # not there, now do long search -- O(n) behavior
+        for member in cls._member_map_.values():
+            if member.value == value:
+                return member
+    raise ValueError("%s is not a valid %s" % (value, cls.__name__))
+temp_enum_dict['__new__'] = __new__
+del __new__
+
+def __repr__(self):
+    return "<%s.%s: %r>" % (
+            self.__class__.__name__, self._name_, self._value_)
+temp_enum_dict['__repr__'] = __repr__
+del __repr__
+
+def __str__(self):
+    return "%s.%s" % (self.__class__.__name__, self._name_)
+temp_enum_dict['__str__'] = __str__
+del __str__
+
+if pyver >= 3.0:
+    def __dir__(self):
+        added_behavior = [
+                m
+                for cls in self.__class__.mro()
+                for m in cls.__dict__
+                if m[0] != '_' and m not in self._member_map_
+                ]
+        return (['__class__', '__doc__', '__module__', ] + added_behavior)
+    temp_enum_dict['__dir__'] = __dir__
+    del __dir__
+
+def __format__(self, format_spec):
+    # mixed-in Enums should use the mixed-in type's __format__, otherwise
+    # we can get strange results with the Enum name showing up instead of
+    # the value
+
+    # pure Enum branch
+    if self._member_type_ is object:
+        cls = str
+        val = str(self)
+    # mix-in branch
+    else:
+        cls = self._member_type_
+        val = self.value
+    return cls.__format__(val, format_spec)
+temp_enum_dict['__format__'] = __format__
+del __format__
+
+
+####################################
+# Python's less than 2.6 use __cmp__
+
+if pyver < 2.6:
+
+    def __cmp__(self, other):
+        if type(other) is self.__class__:
+            if self is other:
+                return 0
+            return -1
+        return NotImplemented
+        raise TypeError("unorderable types: %s() and %s()" % (self.__class__.__name__, other.__class__.__name__))
+    temp_enum_dict['__cmp__'] = __cmp__
+    del __cmp__
+
+else:
+
+    def __le__(self, other):
+        raise TypeError("unorderable types: %s() <= %s()" % (self.__class__.__name__, other.__class__.__name__))
+    temp_enum_dict['__le__'] = __le__
+    del __le__
+
+    def __lt__(self, other):
+        raise TypeError("unorderable types: %s() < %s()" % (self.__class__.__name__, other.__class__.__name__))
+    temp_enum_dict['__lt__'] = __lt__
+    del __lt__
+
+    def __ge__(self, other):
+        raise TypeError("unorderable types: %s() >= %s()" % (self.__class__.__name__, other.__class__.__name__))
+    temp_enum_dict['__ge__'] = __ge__
+    del __ge__
+
+    def __gt__(self, other):
+        raise TypeError("unorderable types: %s() > %s()" % (self.__class__.__name__, other.__class__.__name__))
+    temp_enum_dict['__gt__'] = __gt__
+    del __gt__
+
+
+def __eq__(self, other):
+    if type(other) is self.__class__:
+        return self is other
+    return NotImplemented
+temp_enum_dict['__eq__'] = __eq__
+del __eq__
+
+def __ne__(self, other):
+    if type(other) is self.__class__:
+        return self is not other
+    return NotImplemented
+temp_enum_dict['__ne__'] = __ne__
+del __ne__
+
+def __hash__(self):
+    return hash(self._name_)
+temp_enum_dict['__hash__'] = __hash__
+del __hash__
+
+def __reduce_ex__(self, proto):
+    return self.__class__, (self._value_, )
+temp_enum_dict['__reduce_ex__'] = __reduce_ex__
+del __reduce_ex__
+
+# _RouteClassAttributeToGetattr is used to provide access to the `name`
+# and `value` properties of enum members while keeping some measure of
+# protection from modification, while still allowing for an enumeration
+# to have members named `name` and `value`.  This works because enumeration
+# members are not set directly on the enum class -- __getattr__ is
+# used to look them up.
+
+@_RouteClassAttributeToGetattr
+def name(self):
+    return self._name_
+temp_enum_dict['name'] = name
+del name
+
+@_RouteClassAttributeToGetattr
+def value(self):
+    return self._value_
+temp_enum_dict['value'] = value
+del value
+
+@classmethod
+def _convert(cls, name, module, filter, source=None):
+    """
+    Create a new Enum subclass that replaces a collection of global constants
+    """
+    # convert all constants from source (or module) that pass filter() to
+    # a new Enum called name, and export the enum and its members back to
+    # module;
+    # also, replace the __reduce_ex__ method so unpickling works in
+    # previous Python versions
+    module_globals = vars(_sys.modules[module])
+    if source:
+        source = vars(source)
+    else:
+        source = module_globals
+    members = dict((name, value) for name, value in source.items() if filter(name))
+    cls = cls(name, members, module=module)
+    cls.__reduce_ex__ = _reduce_ex_by_name
+    module_globals.update(cls.__members__)
+    module_globals[name] = cls
+    return cls
+temp_enum_dict['_convert'] = _convert
+del _convert
+
+Enum = EnumMeta('Enum', (object, ), temp_enum_dict)
+del temp_enum_dict
+
+# Enum has now been created
+###########################
+
+class IntEnum(int, Enum):
+    """Enum where members are also (and must be) ints"""
+
+def _reduce_ex_by_name(self, proto):
+    return self.name
+
+def unique(enumeration):
+    """Class decorator that ensures only unique members exist in an enumeration."""
+    duplicates = []
+    for name, member in enumeration.__members__.items():
+        if name != member.name:
+            duplicates.append((name, member.name))
+    if duplicates:
+        duplicate_names = ', '.join(
+                ["%s -> %s" % (alias, name) for (alias, name) in duplicates]
+                )
+        raise ValueError('duplicate names found in %r: %s' %
+                (enumeration, duplicate_names)
+                )
+    return enumeration