python如何查找在线帮助？

>>>help(input)

    Help on built-in function input in module builtins:

    input(prompt=None, /)

        Read a string from standard input.  The trailing newline is stripped.

    The prompt string, if given, is printed to standard output without a

    trailing newline before reading input.

    If the user hits EOF (*nix: Ctrl-D, Windows: Ctrl-Z+Return), raise EOFError.

    On *nix systems, readline is used if available.