req.py 文件源码

def egg_info_path(self, filename):
        if self._egg_info_path is None:
            if self.editable:
                base = self.source_dir
            else:
                base = os.path.join(self.source_dir, 'pip-egg-info')
            filenames = os.listdir(base)
            if self.editable:
                filenames = []
                for root, dirs, files in os.walk(base):
                    for dir in vcs.dirnames:
                        if dir in dirs:
                            dirs.remove(dir)
                    # Iterate over a copy of ``dirs``, since mutating
                    # a list while iterating over it can cause trouble.
                    # (See https://github.com/pypa/pip/pull/462.)
                    for dir in list(dirs):
                        # Don't search in anything that looks like a virtualenv environment
                        if (os.path.exists(os.path.join(root, dir, 'bin', 'python'))
                            or os.path.exists(os.path.join(root, dir, 'Scripts', 'Python.exe'))):
                            dirs.remove(dir)
                        # Also don't search through tests
                        if dir == 'test' or dir == 'tests':
                            dirs.remove(dir)
                    filenames.extend([os.path.join(root, dir)
                                     for dir in dirs])
                filenames = [f for f in filenames if f.endswith('.egg-info')]

            if not filenames:
                raise InstallationError('No files/directories in %s (from %s)' % (base, filename))
            assert filenames, "No files/directories in %s (from %s)" % (base, filename)

            # if we have more than one match, we pick the toplevel one.  This can
            # easily be the case if there is a dist folder which contains an
            # extracted tarball for testing purposes.
            if len(filenames) > 1:
                filenames.sort(key=lambda x: x.count(os.path.sep) +
                                             (os.path.altsep and
                                              x.count(os.path.altsep) or 0))
            self._egg_info_path = os.path.join(base, filenames[0])
        return os.path.join(self._egg_info_path, filename)