Update six to version 1.13.0

lib/six.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2010-2017 Benjamin Peterson
+# Copyright (c) 2010-2019 Benjamin Peterson
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@ import sys
 import types
 
 __author__ = "Benjamin Peterson <benjamin@python.org>"
-__version__ = "1.11.0"
+__version__ = "1.13.0"
 
 
 # Useful for very coarse version differentiation.
@@ -255,8 +255,10 @@ _moved_attributes = [
     MovedAttribute("zip_longest", "itertools", "itertools", "izip_longest", "zip_longest"),
     MovedModule("builtins", "__builtin__"),
     MovedModule("configparser", "ConfigParser"),
+    MovedModule("collections_abc", "collections", "collections.abc" if sys.version_info >= (3, 3) else "collections"),
     MovedModule("copyreg", "copy_reg"),
     MovedModule("dbm_gnu", "gdbm", "dbm.gnu"),
+    MovedModule("dbm_ndbm", "dbm", "dbm.ndbm"),
     MovedModule("_dummy_thread", "dummy_thread", "_dummy_thread"),
     MovedModule("http_cookiejar", "cookielib", "http.cookiejar"),
     MovedModule("http_cookies", "Cookie", "http.cookies"),
@@ -637,6 +639,7 @@ if PY3:
     import io
     StringIO = io.StringIO
     BytesIO = io.BytesIO
+    del io
     _assertCountEqual = "assertCountEqual"
     if sys.version_info[1] <= 1:
         _assertRaisesRegex = "assertRaisesRegexp"
@@ -824,7 +827,15 @@ def with_metaclass(meta, *bases):
     class metaclass(type):
 
         def __new__(cls, name, this_bases, d):
-            return meta(name, bases, d)
+            if sys.version_info[:2] >= (3, 7):
+                # This version introduced PEP 560 that requires a bit
+                # of extra care (we mimic what is done by __build_class__).
+                resolved_bases = types.resolve_bases(bases)
+                if resolved_bases is not bases:
+                    d['__orig_bases__'] = bases
+            else:
+                resolved_bases = bases
+            return meta(name, resolved_bases, d)
 
         @classmethod
         def __prepare__(cls, name, this_bases):
@@ -844,10 +855,71 @@ def add_metaclass(metaclass):
                 orig_vars.pop(slots_var)
         orig_vars.pop('__dict__', None)
         orig_vars.pop('__weakref__', None)
+        if hasattr(cls, '__qualname__'):
+            orig_vars['__qualname__'] = cls.__qualname__
         return metaclass(cls.__name__, cls.__bases__, orig_vars)
     return wrapper
 
 
+def ensure_binary(s, encoding='utf-8', errors='strict'):
+    """Coerce **s** to six.binary_type.
+
+    For Python 2:
+      - `unicode` -> encoded to `str`
+      - `str` -> `str`
+
+    For Python 3:
+      - `str` -> encoded to `bytes`
+      - `bytes` -> `bytes`
+    """
+    if isinstance(s, text_type):
+        return s.encode(encoding, errors)
+    elif isinstance(s, binary_type):
+        return s
+    else:
+        raise TypeError("not expecting type '%s'" % type(s))
+
+
+def ensure_str(s, encoding='utf-8', errors='strict'):
+    """Coerce *s* to `str`.
+
+    For Python 2:
+      - `unicode` -> encoded to `str`
+      - `str` -> `str`
+
+    For Python 3:
+      - `str` -> `str`
+      - `bytes` -> decoded to `str`
+    """
+    if not isinstance(s, (text_type, binary_type)):
+        raise TypeError("not expecting type '%s'" % type(s))
+    if PY2 and isinstance(s, text_type):
+        s = s.encode(encoding, errors)
+    elif PY3 and isinstance(s, binary_type):
+        s = s.decode(encoding, errors)
+    return s
+
+
+def ensure_text(s, encoding='utf-8', errors='strict'):
+    """Coerce *s* to six.text_type.
+
+    For Python 2:
+      - `unicode` -> `unicode`
+      - `str` -> `unicode`
+
+    For Python 3:
+      - `str` -> `str`
+      - `bytes` -> decoded to `str`
+    """
+    if isinstance(s, binary_type):
+        return s.decode(encoding, errors)
+    elif isinstance(s, text_type):
+        return s
+    else:
+        raise TypeError("not expecting type '%s'" % type(s))
+
+
+
 def python_2_unicode_compatible(klass):
     """
     A decorator that defines __unicode__ and __str__ methods under Python 2.