def load_pip_requirements(self, files_map=None, freeze=True):
        if files_map is None:
            files_map = self.default_pip_files
        for group, requirements_txt in files_map.items():
            path = Path(requirements_txt)
            if not path.exists() and group.lower() == "all" and freeze:
                cmd = envoy.run("pip freeze")
                self[group].loads(cmd.std_out)
            elif path.exists():
                self[group].load(path)
def _remainingpats(pat, prefix):
    """list of patterns with prefix stripped

    >>> _remainingpats("a/b/c", "")
    ['a/b/c']
    >>> _remainingpats("a/b/c", "a")
    ['b/c']
    >>> _remainingpats("a/b/c", "a/b")
    ['c']
    >>> _remainingpats("a/b/c", "a/b/c")
    []
    >>> _remainingpats("", "")
    []
    """
    if prefix:
        if prefix == pat:
            return []
        else:
            assert pat[len(prefix)] == "/"
            return [pat[len(prefix) + 1 :]]
    else:
        if pat:
            return [pat]
        else:
            return []