目录python
1、re.findall函数介绍正则表达式
2、代码以下数组
它在re.py中有定义:this
def findall(pattern, string, flags=0): """Return a list of all non-overlapping matches in the string. If one or more capturing groups are present in the pattern, return a list of groups; this will be a list of tuples if the pattern has more than one group. Empty matches are included in the result.""" return _compile(pattern, flags).findall(string)
返回string中全部与pattern匹配的所有字符串,返回形式为数组。spa
后面会讲解代码里的各个部分,先列出来~code
import re str = 'aabbabaabbaa' #一个"."就是匹配除 \n (换行符)之外的任意一个字符 print(re.findall(r'a.b',str))#['aab', 'aab'] #*前面的字符出现0次或以上 print(re.findall(r'a*b',str))#['aab', 'b', 'ab', 'aab', 'b'] #贪婪,匹配从.*前面为开始到后面为结束的全部内容 print(re.findall(r'a.*b',str))#['aabbabaabb'] #非贪婪,遇到开始和结束就进行截取,所以截取屡次符合的结果,中间没有字符也会被截取 print(re.findall(r'a.*?b',str))#['aab', 'ab', 'aab'] #非贪婪,与上面同样,只是与上面的相比多了一个括号,只保留括号的内容 print(re.findall(r'a(.*?)b',str))#['a', '', 'a'] str = '''aabbab aabbaa bb'''#后面多加了2个b #没有把最后一个换行的aab算进来 print(re.findall(r'a.*?b',str))#['aab', 'ab', 'aab'] #re.S不会对\n进行中断 print(re.findall(r'a.*?b',str,re.S))#['aab', 'ab', 'aab', 'aa\n b']
字符串是字符串
str = 'aabbabaabbaa'
print(re.findall(r'a.b',str))
['aab', 'aab']
print(re.findall(r'a*b',str))
['aab', 'b', 'ab', 'aab', 'b']
print(re.findall(r'a.*b',str))
['aabbabaabb']
print(re.findall(r'a.*?b',str))
['aab', 'ab', 'aab']
print(re.findall(r'a(.*?)b',str))
['a', '', 'a']
str = '''aabbab aabbaa bb'''
print(re.findall(r'a.*?b',str))
['aab', 'ab', 'aab']
print(re.findall(r'a.*?b',str,re.S))
['aab', 'ab', 'aab', 'aa\n b']