python中正则表达式的处理函数

python中re模块中体重了基于模式的字符串处理能力，比如替换字符串，以及根据界定符对字符串进行分解等。

点击(此处)折叠或打开import re

tststr = 'This sentence ends in 5 stars *****'
str1 = "1,2,3,4,5,6,7"
str2 = "1+2x*3-y"

formatstr = '%-34s: %s' # string to format output

print formatstr % ("Original string" ,tststr)

tststr = re.sub( r'\*' , r'^' , tststr)   #替换子字符串
print formatstr % ( '^ substitute for *' , tststr)

tststr = re.sub( r'stars' , 'carets' , tststr )
print formatstr % ('carets substitute for stars' , tststr)

tststr = formatstr % ( "Every word replaced by 'hello'" ,
            re.sub(r'\w+' , 'hello' , tststr) )

print formatstr % ('Replace str1 first 3 digits by "digit"' ,
            re.sub(r'\d' , 'digit' , str1 , 3) )   #将数字进行替换，并指定替换的最多次数

print formatstr % ('Splitting' + str1 , re.split(r',' , str1))

print formatstr % ("Splitting " + str2 , re.split(r'[+\-*/%]' , str2))
#类只能个出现的任何字符（^ 和 - 除外）都会被解释成字面意义的字符，所以 $ ， + ， * 等元字符无需转义 点击(此处)折叠或打开运行结果如下：
Original string : This sentence ends in 5 stars *****
^ substitute for * : This sentence ends in 5 stars ^^^^^
carets substitute for stars : This sentence ends in 5 carets ^^^^^
Replace first 3 digits by "digit" : digit,digit,digit,4,5,6,7
Splitting1,2,3,4,5,6,7 : ['1', '2', '3', '4', '5', '6', '7']
Splitting 1+2x*3-y : ['1', '2x', '3', 'y']