Rename __version__.py to _version.py

This avoids a name collision with mypackage.__version__
(the string).

In addition, the single underscore shows it's a 'private' module
that has no special meaning to the Python interpreter.

mypackage/__init__.py

@@ -1,5 +1,5 @@
 
-from .__version__ import VERSION
+from ._version import VERSION
 __version__ = '.'.join(map(str, VERSION))
 
 from .core import *

setup.py

@@ -45,10 +45,10 @@ try:
 except FileNotFoundError:
     long_description = DESCRIPTION
 
-# Load the package's __version__.py module as a dictionary.
+# Load the package's _version.py module as a dictionary.
 about = {}
 if not VERSION:
-    with open(os.path.join(here, NAME, '__version__.py')) as f:
+    with open(os.path.join(here, NAME, '_version.py')) as f:
         exec(f.read(), about)
         about['__version__'] = '.'.join(map(str, about['VERSION']))
 else: