__init__.py 文件源码

def check_version_conflict(self):
        if self.key == 'setuptools':
            # ignore the inevitable setuptools self-conflicts  :(
            return

        nsp = dict.fromkeys(self._get_metadata('namespace_packages.txt'))
        loc = normalize_path(self.location)
        for modname in self._get_metadata('top_level.txt'):
            if (modname not in sys.modules or modname in nsp
                    or modname in _namespace_packages):
                continue
            if modname in ('pkg_resources', 'setuptools', 'site'):
                continue
            fn = getattr(sys.modules[modname], '__file__', None)
            if fn and (normalize_path(fn).startswith(loc) or
                       fn.startswith(self.location)):
                continue
            issue_warning(
                "Module %s was already imported from %s, but %s is being added"
                " to sys.path" % (modname, fn, self.location),
            )