python基础===拆分字符串，和拼接字符串

给定某字符，只需要保留其中的有效汉字或者字母，数字之类的。去掉特殊符号或者以某种格式进行拆分的时候，就可以采用re.split的方法。例如

=============================== RESTART: Shell ===============================
>>> s = '''Python 3.6.1 (v3.6.1:69c0db5, Mar 21 2017, 18:41:36) [MSC v.1900 64 bit (AMD64)] on win32
Type "copyright", "credits" or "license()" for more information.'''
>>> s
'Python 3.6.1 (v3.6.1:69c0db5, Mar 21 2017, 18:41:36) [MSC v.1900 64 bit (AMD64)] on win32\nType "copyright", "credits" or "license()" for more information.'
>>> #现在要对s拆分，去掉里面多余的字符，只提取 数字，字母这些有效字符。
>>>
>>> import re
>>> x = re.split(r'[.(:,[)" ]', s)    #把特殊符号和空格都作为拆分条件输入
['Python', '', '', '', '', 'v3', '', '', '69c0db5', '', 'Mar', '', '', '', '', '', '', '', '', 'MSC', 'v', '', '', 'bit', '', 'AMD64', ']', 'on', 'win32\nType', '', 'copyright', '', '', '', 'credits', '', 'or', '', 'license', '', '', '', 'for', 'more', 'information', '']
>>>
>>> words = [i for i in x if i]
>>> words
['Python', '', '', '', 'v3', '', '', '69c0db5', 'Mar', '', '', '', '', '', 'MSC', 'v', '', '', 'bit', 'AMD64', ']', 'on', 'win32\nType', 'copyright', 'credits', 'or', 'license', 'for', 'more', 'information']
>>> 

使用S.join() 方法拼接：

>>> #字符串的拼接
>>>
>>> help(str.join)
Help on method_descriptor:

join(...)
    S.join(iterable) -> str

    Return a string which is the concatenation of the strings in the
    iterable.  The separator between elements is S.

>>> l = list(range(1,9))
>>>
>>> s = "".join([str(i) for i in l])
>>> s
''
>>> s = "".join(str(i) for i in l)
>>> s
''
>>>