python帮助函数 type dir help

>>> li = []
>>> type(li)
<type 'list'>
>>>

>>> dir(li)
[... ...]
>>> dir('list') #list类
[... ...]
>>>

>>> help(li)
"""Help on class list in module __builtin__:

class list(object)
 | list() -> new list
 | list(sequence) -> new list initialized from sequence's items
 |
 | Methods defined here:
 |
 | __add__(...)
 | x.__add__(y) <==> x+y"""
>>> help('list')
"""Help on class list in module __builtin__:

class list(object)
 | list() -> new list
 | list(sequence) -> new list initialized from sequence's items
 |
 | Methods defined here:
 |
 | __add__(...)
 | x.__add__(y) <==> x+y"""