Add future 0.18.2

lib/libfuturize/fixes/fix_absolute_import.py

@@ -0,0 +1,91 @@
+"""
+Fixer for import statements, with a __future__ import line.
+
+Based on lib2to3/fixes/fix_import.py, but extended slightly so it also
+supports Cython modules.
+
+If spam is being imported from the local directory, this import:
+    from spam import eggs
+becomes:
+    from __future__ import absolute_import
+    from .spam import eggs
+
+and this import:
+    import spam
+becomes:
+    from __future__ import absolute_import
+    from . import spam
+"""
+
+from os.path import dirname, join, exists, sep
+from lib2to3.fixes.fix_import import FixImport
+from lib2to3.fixer_util import FromImport, syms
+from lib2to3.fixes.fix_import import traverse_imports
+
+from libfuturize.fixer_util import future_import
+
+
+class FixAbsoluteImport(FixImport):
+    run_order = 9
+
+    def transform(self, node, results):
+        """
+        Copied from FixImport.transform(), but with this line added in
+        any modules that had implicit relative imports changed:
+
+            from __future__ import absolute_import"
+        """
+        if self.skip:
+            return
+        imp = results['imp']
+
+        if node.type == syms.import_from:
+            # Some imps are top-level (eg: 'import ham')
+            # some are first level (eg: 'import ham.eggs')
+            # some are third level (eg: 'import ham.eggs as spam')
+            # Hence, the loop
+            while not hasattr(imp, 'value'):
+                imp = imp.children[0]
+            if self.probably_a_local_import(imp.value):
+                imp.value = u"." + imp.value
+                imp.changed()
+                future_import(u"absolute_import", node)
+        else:
+            have_local = False
+            have_absolute = False
+            for mod_name in traverse_imports(imp):
+                if self.probably_a_local_import(mod_name):
+                    have_local = True
+                else:
+                    have_absolute = True
+            if have_absolute:
+                if have_local:
+                    # We won't handle both sibling and absolute imports in the
+                    # same statement at the moment.
+                    self.warning(node, "absolute and local imports together")
+                return
+
+            new = FromImport(u".", [imp])
+            new.prefix = node.prefix
+            future_import(u"absolute_import", node)
+            return new
+
+    def probably_a_local_import(self, imp_name):
+        """
+        Like the corresponding method in the base class, but this also
+        supports Cython modules.
+        """
+        if imp_name.startswith(u"."):
+            # Relative imports are certainly not local imports.
+            return False
+        imp_name = imp_name.split(u".", 1)[0]
+        base_path = dirname(self.filename)
+        base_path = join(base_path, imp_name)
+        # If there is no __init__.py next to the file its not in a package
+        # so can't be a relative import.
+        if not exists(join(dirname(base_path), "__init__.py")):
+            return False
+        for ext in [".py", sep, ".pyc", ".so", ".sl", ".pyd", ".pyx"]:
+            if exists(base_path + ext):
+                return True
+        return False