15.2 正则表达式使用的特殊符号和字符: 现在,我们来介绍最常用的元字符(metacharacters)----特殊字符和符号, 正式它们赋予了正则表达式强大的功能和灵活性。 符号 literal 匹配字符串的值 foo import re a='foo2' if (re.match("foo",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a15.py 1111 re1|re2 匹配正则表达式re1或re2 foo|bar import re a='bar2' if (re.match("foo|bar",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a15.py 1111 . 匹配任何字符(换行符外) b.b import re a="aib" if (re.match("a.b",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a15.py 1111 import re a="a\nb" if (re.match("a.b",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a15.py Process finished with exit code 0 import re a="a\nb" print a # if (re.match("a.b",a)): # print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a15.py a b ^ 匹配字符串的开始 ^Dear * 匹配前面出现的正则表达式零次或多次 [A-Za-z0-9]* import re a="99" if (re.match("[A-Z]*",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a15.py 1111 import re a="^^" if (re.match("[A-Z]*",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a15.py 1111 + 匹配前面出现的正则表达式一次或多次 import re a="^^" if (re.match("[A-Z]+",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a15.py Process finished with exit code 0 import re a="X" if (re.match("[A-Z]+",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a15.py 1111 ? 匹配前面出现的正则表达式零次或一次 import re a="go" if (re.match("goo?",a)): print '1111' import re a="god" if (re.match("go?d",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a15.py 1111 import re a="good" if (re.match("go?d",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a15.py Process finished with exit code 0 import re a="g322d" if (re.match("g[0-9]{3}d",a)): print '1111' {M,N} 匹配重复出现M此到N次的正则表达式 【0-9】{5,9} import re a="g32525d" if (re.match("g[0-9]{3,5}d",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a15.py 1111 import re a="aaaa" if (re.match("[aeiou]",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a15.py 1111 import re a="a44" p=re.compile("(.*?)[0-9]") m=p.match(a) print m.group(1) C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a15.py a \d 匹配任何数字,和[0-9]一样(\D是\d的反义:任何非数符字) import re a="data1.txt" if (re.match("data\d.txt",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a14.py 1111 import re a="data1.txt" if (re.match("data\d.txt",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a14.py 1111 \w 匹配任何数字字母字符,和[A-Za-z0-9]相同(\W是\w的反义) import re a="anb" if (re.match("[A-Za-z]\w+b",a)): print '1111' C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a14.py 1111
python 元字符
猜你喜欢
转载自blog.csdn.net/zhaoyangjian724/article/details/80453091
今日推荐
周排行