Prevent loading of pyc files when the py file has disappeared.

gistfile1.py

import imp
import os
import os.path
import stat
import sys

class pycSanity(object):
    def __new__(cls, *args):
        obj = super(pycSanity, cls).__new__(cls)
        obj.args = args
        return obj

    @classmethod
    def find_module(cls, module_name, package_path):
        try:
            return cls(module_name, *imp.find_module(module_name, package_path))
        except ImportError as exc:
            return None

    def load_module(self, fullname):
        load_pathname = self.args[2]
        if load_pathname[:-1].endswith('.py') and os.path.isfile(load_pathname):
            source_name = os.path.splitext(load_pathname)[0] + '.py'
            if not os.path.isfile(source_name):
                return None
        return (
            sys.modules.get(self.args[0]) or
            imp.load_module(*self.args)
        )
sys.meta_path.append(pycSanity)