literals.py 文件源码

def escape(m):
    all, tail = m.group(0, 1)
    assert all.startswith("\\")
    esc = simple_escapes.get(tail)
    if esc is not None:
        return esc
    elif tail.startswith("x"):
        return chr(convert_hex(tail, 2))
    elif tail.startswith('u'):
        return unichr(convert_hex(tail, 4))
    elif tail.startswith('U'):
        return unichr(convert_hex(tail, 8))
    elif tail.startswith('N'):
        import unicodedata
        try:
            return unicodedata.lookup(tail[1:-1])
        except KeyError:
            raise ValueError("undefined character name %r" % tail[1:-1])
    else:
        try:
            return chr(int(tail, 8))
        except ValueError:
            raise ValueError("invalid octal string escape ('\\%s')" % tail)