python帮助说明

用的了python写脚本，也只是理解后ctrl+s，代码复用。当遇到陌生的模块的时候，如何查询，一直是很模糊的概念。今天记录点，也当时工具笔记了。

type(var_1)查看var_1变量类型

help(var_1) ERROR,应该是help(type(var_1))，只能查看类型或者函数的帮助

>>> a='111'
>>> a
'111'
>>> help(a)
no Python documentation found for '111'

>>> help(type(a))
Help on class str in module __builtin__:

class str(basestring)
 |  str(object='') -> string
 |

-----------------------------


>>> help(split)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'split' is not defined
>>> help(str.split)
Help on method_descriptor:

split(...)
    S.split([sep [,maxsplit]]) -> list of strings

    Return a list of the words in the string S, using sep as the
    delimiter string.  If maxsplit is given, at most maxsplit
    splits are done. If sep is not specified or is None, any
    whitespace string is a separator and empty strings are removed
    from the result.

dir(var_1) 查看var_1对象所有的方法
关于两条下划线的代表什么意思，参见这篇python下划线使用注意

疑问1：只有方法，没有属性么
疑问2：为什么有些加下划线了，有些并没有加上。

>>> dir(a)
['__add__', '__class__', '__contains__', '__delattr__', '__doc__', '__eq__', '__
format__', '__ge__', '__getattribute__', '__getitem__', '__getnewargs__', '__get
slice__', '__gt__', '__hash__', '__init__', '__le__', '__len__', '__lt__', '__mo
d__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__',
 '__rmod__', '__rmul__', '__setattr__', '__sizeof__', '__str__', '__subclasshook
__', '_formatter_field_name_split', '_formatter_parser', 'capitalize', 'center',
 'count', 'decode', 'encode', 'endswith', 'expandtabs', 'find', 'format', 'index
', 'isalnum', 'isalpha', 'isdigit', 'islower', 'isspace', 'istitle', 'isupper',
'join', 'ljust', 'lower', 'lstrip', 'partition', 'replace', 'rfind', 'rindex', '
rjust', 'rpartition', 'rsplit', 'rstrip', 'split', 'splitlines', 'startswith', '
strip', 'swapcase', 'title', 'translate', 'upper', 'zfill']
>>>