匹配搜索 match，search，findall区别

匹配搜索 match，search，findall区别

match首字母搜索匹配，匹配即停止

import re
re.match(r'de','de8ug').group() 

'de'

re.match(r'de','8ugde').group()  

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

AttributeError                            Traceback (most recent call last)

<ipython-input-37-4da79a63dcbc> in <module>()
----> 1 re.match(r'de','8ugde').group()  # 只能首字母匹配

AttributeError: 'NoneType' object has no attribute 'group'

search所有字母搜索匹配，匹配即停止

re.search(r'de','8ugde').group() 

'de'

re.search(r'de','de8ug').group() 

'de'

re.search('de','8ugde 88deug').group() 

'de'

match和search结合group使用

re.match(r"(\w+) (\w+)", "Isaac Newton, physicist").group() # 首字母匹配,匹配即停止

'Isaac Newton'

re.match(r"(\w+) (\w+)", "Isaac Newton, physicist").group(1)

'Isaac'

re.match(r"(\w+) (\w+)", "Isaac Newton, physicist").group(2)

'Newton'

re.search(r"(\w+) (\w+)", "IsaacNewton, physicist fsdf").group()

'physicist fsdf'

re.search(r"(\w+) (\w+)", "Isaac Newton, physicist fsdf").group()  # 所有字母匹配,匹配即停止

'Isaac Newton'

re.search(r"(\w+) (\w+)", "Isaac Newton, physicist fsdf").group(1)

'Isaac'

re.search(r"(\w+) (\w+)", "Isaac Newton, physicist fsdf").group(2)

'Newton'

findall 找到所有匹配的内容

re.findall(r"(\w+) (\w+)", "Isaac Newton, physicist fsdf") # 找到所有匹配的内容,返回一个列表

[('Isaac', 'Newton'), ('physicist', 'fsdf')]

re.findall(r"(\w+) (\w+)", "Isaac Newton, physicist fsdf")[0]

('Isaac', 'Newton')

re.findall(r"(\w+) (\w+)", "Isaac Newton, physicist fsdf")[1]

('physicist', 'fsdf')

返回类型

type(re.match(r"(\w+) (\w+)", "Isaac Newton, physicist").group()) # 返回字符串

str

type(re.search(r"(\w+) (\w+)", "Isaac Newton, physicist").group()) # 返回字符串

str

type(re.findall(r"(\w+) (\w+)", "Isaac Newton, physicist fsdf"))  # 返回列表

list