python help擷取協助

http://woodpecker.org.cn/abyteofpython_cn/chinese/ch03s06.html   

1.

     如果你需要某個Python函數或語句的快速資訊協助，那麼你可以使用內建的help功能。尤其在你使用帶提示符的命令列的時候，它十分有用。比如，運行help(str)——這會顯示str類的協助。str類用於儲存你的程式使用的各種文本（字串）。類將在後面物件導向編程的章節詳細解釋。

    按q退出協助。
     類似地，你可以擷取Python中幾乎所有東西的資訊。使用help()去學習更多關於help本身的東西！

 help('print')
      你應該注意到我特意在“print”上使用了引號，那樣Python就可以理解我是希望擷取關於“print”的協助而不是想要它列印東西

http://askubuntu.com/questions/230994/python-2-7-no-documentation-found-when-typing-helpprint

2.

Question:

I have just installed Python 2.7 and Python 3.2 on my Ubuntu 12.04 (32 bit).

However if I open a Python 2.7 shell (python from a terminal) when I type help('print') I get the following message:
no documentation found for 'print'

How can I get to use the documentation in Python 2.7 as well?

Answer:

This looks like a bug of Python 2 as something like help("dir") works properly. It probably does not work because print is a special keyword, unlike Python 3. Stick to Python 3 or run the following command instead of help("print"):

help("__builtin__.print")