def get_installed_pypackages():
    return {p.project_name.lower(): p for p in pkg_resources.working_set}
def _expandsets(kindpats, ctx):
    """Returns the kindpats list with the 'set' patterns expanded."""
    fset = set()
    other = []

    for kind, pat, source in kindpats:
        if kind == "set":
            if not ctx:
                raise error.ProgrammingError("fileset expression with no " "context")
            s = ctx.getfileset(pat)
            fset.update(s)
            continue
        other.append((kind, pat, source))
    return fset, other