Python -- 操作字符串[3/3]

 1，splitlines()

yuan@ThinkPad-SL510:~$ ipython -nobanner

In [1]: multiline_string = """This
   ...: is
   ...: a multiline
   ...: piece of
   ...: text"""

In [2]: multiline_string.spli
multiline_string.split       multiline_string.splitlines

In [2]: multiline_string.split()
Out[2]: ['This', 'is', 'a', 'multiline', 'piece', 'of', 'text']

In [3]: lines = multiline_string.splitlines()

In [4]: lines
Out[4]: ['This', 'is', 'a multiline', 'piece of', 'text']

糊涂了?仔细看13行和18行的a multilines。

 

2，join()

yuan@ThinkPad-SL510:~$ ipython -nobanner

In [1]: some_list = ['one','two','three','four']

In [2]: ','.join(some_list)
Out[2]: 'one,two,three,four'

In [3]: '\t'.join(some_list)
Out[3]: 'one\ttwo\tthree\tfour'

In [4]: ''.join(some_list)
Out[4]: 'onetwothreefour'

很简单不是吗?

没那么简单，请看：

 

yuan@ThinkPad-SL510:~$ ipython -nobanner

In [1]: some_list = range(10)

In [2]: some_list
Out[2]: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

In [6]: ",".join(some_list) --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /home/yuan/<ipython console> in <module>() TypeError: sequence item 0: expected string, int found


In [4]: ",".join([str(i) for i in some_list])
Out[4]: '0,1,2,3,4,5,6,7,8,9'

In [5]: ",".join(str(i) for i in some_list)
Out[5]: '0,1,2,3,4,5,6,7,8,9'

很显然join只能处理字符串序列，str()即可。

 

3，replace()

yuan@ThinkPad-SL510:~$ ipython -nobanner

In [1]: replacable_string = "trancendental hibernational nation"

In [2]: replacable_string.replace("nation","natty")
Out[2]: 'trancendental hibernattyal natty'

这个没啥好说的，很简单

但是必须说下：replace()和前边说的strip()一样，会创建一个新字符串，而不是对字符串进行行内修改。