python之模块3

RE模块使用方法

（1）finditer  返回迭代器

（2）search：只匹配第一个结果

import re
res=re.search("\d+","djksf34sa2")
print(re.search("\d+","djksf34sa2"))
>>
<_sre.SRE_Match object; span=(5, 7), match='34'>

print(res.group)
>>
34

（3）match:只在字符串开始的位置匹配

print(re.match("\d+","22djksf34sa2"))
>>
<_sre.SRE_Match object; span=(0, 2), match='22'>

res=re.match("\d+","22djksf34sa2")
print(res.group())
>>
22

　（4）split:分割

print(re.split("\d+","fhd123jsk7fhihi5flb5"))
>>
['fhd', 'jsk', 'fhihi', 'flb', '']

限定次数
print(re.split("\d+","fhd123jsk7fhihi5flb5",2))
>>
['fhd', 'jsk', 'fhihi5flb5']　

（5）sub:替换   需要三个参数

print(re.sub("\d+","A","hello 24sdf2"))
>>
hello AsdfA

print(re.sub("\d+","A","hello 24sdf2",1))#添加替换次数
>>
hello Asdf2

print(re.subn("\d+","A","hello 24sdf2",1))#返回一个元组，并显示替换次数
>>
('hello Asdf2', 1)

（6）compile:编译方法

c=re.compile("\d+")
print(c.findall("hello123wof55"))#=======re.findall(“\d+”,”hello123wof55”)
>>
['123', '55']