install.py 文件源码

def handle_extra_path (self):

        if self.extra_path is None:
            self.extra_path = self.distribution.extra_path

        if self.extra_path is not None:
            if type(self.extra_path) is StringType:
                self.extra_path = string.split(self.extra_path, ',')

            if len(self.extra_path) == 1:
                path_file = extra_dirs = self.extra_path[0]
            elif len(self.extra_path) == 2:
                (path_file, extra_dirs) = self.extra_path
            else:
                raise DistutilsOptionError, \
                      ("'extra_path' option must be a list, tuple, or "
                      "comma-separated string with 1 or 2 elements")

            # convert to local form in case Unix notation used (as it
            # should be in setup scripts)
            extra_dirs = convert_path(extra_dirs)

        else:
            path_file = None
            extra_dirs = ''

        # XXX should we warn if path_file and not extra_dirs? (in which
        # case the path file would be harmless but pointless)
        self.path_file = path_file
        self.extra_dirs = extra_dirs

    # handle_extra_path ()