pypa/pip — pull request #646 by qwcode (2012-08-18 22:35:49+00:00)
Title: fix for #638  (__pycache__ file removal)

a fix for issue #638 that works for py3.2+ or the debian-packaged pypy (that uses `__pycache__`)

makes use of `imp.cache_from_source`

notice that I added specific `import` calls into multiple tests to makes sure we were actually testing the removal of `__pycache__` files.

also notice I had to repackage the test `parent-0.1` distribution to remove a twisted import.