Python 正则表达式中的group参数使用

#!/usr/bin/python
# -*- coding: UTF-8 -*-

import re


def dirp(iter):  # 定义函数dirp
    return [i for i in dir(iter) if not i.startswith(‘_‘)]  # 将dir(iter)的值中过滤掉前面带_的数据后，赋值给变量i，然后将i的值赋值给dirp函数


# 定义一个变量a，并将字符串“name”赋值给变量a，字符串前面加个r是告诉编译器这个string是个raw string,不要转意
a = r"name"
print(dirp(re))
# 定义一个变量match
match = re.search(a, "my name is sam,what is you name?")
if match:
    print(match.group())            # 在字符串“my name is sam,what is you name?”中搜索“name”,如果存在就打印出来
    print(match.start())            # 如果有就打印该字符的开始位置，字符串“my name is sam,what is you name?”的m是第0位
    print(match.end())              # 打印字符串的结束位置
    print(match.span())             # 打印字符串的开始位置和结束位置
    print(type(match.group))        # 打印match.group()的类型


www = r"www.cnblogs.com"
print(re.match(r"(www).(cnblogs).(com)", www).group())               # 打印全部匹配结果，注意每个括号匹配值必须接上一个括号，否则会报错
print(re.match(r"(www).(cnblogs).(com)", www).group(1))              # 打印第一个括号中的匹配结果
print(re.match(r"(www).(cnblogs).(com)", www).group(2))              # 打印第二个括号中的匹配结果
print(re.match(r"(www).(cnblogs).(com)", www).group(3))              # 打印第三个括号中的匹配结果
print(re.match(r"(www).cnblogs.(com)", www).group(2))                # 打印第二个括号中的匹配结果

line = "Cars are smarter than dog."

matchObj = re.match(r‘(.*) are (.*?) .*‘, line, re.M | re.I)

if matchObj:
    print("matchObj.group(): ", matchObj.group())
    print("matchObj.group(1): ", matchObj.group(1))
    print("matchObj.group(2): ", matchObj.group(2))
else:
    print("No match!!")

C:\Users\Administrator\AppData\Local\Programs\Python\Python35-32\python.exe C:\Users\Administrator\Desktop\mypython\re_test.py
[‘A‘, ‘ASCII‘, ‘DEBUG‘, ‘DOTALL‘, ‘I‘, ‘IGNORECASE‘, ‘L‘, ‘LOCALE‘, ‘M‘, ‘MULTILINE‘, ‘S‘, ‘Scanner‘, ‘T‘, ‘TEMPLATE‘, ‘U‘, ‘UNICODE‘, ‘VERBOSE‘, ‘X‘, ‘compile‘, ‘copyreg‘, ‘error‘, ‘escape‘, ‘findall‘, ‘finditer‘, ‘fullmatch‘, ‘match‘, ‘purge‘, ‘search‘, ‘split‘, ‘sre_compile‘, ‘sre_parse‘, ‘sub‘, ‘subn‘, ‘sys‘, ‘template‘]
name
3
7
(3, 7)
<class ‘builtin_function_or_method‘>
www.cnblogs.com
www
cnblogs
com
com
matchObj.group():  Cars are smarter than dog.
matchObj.group(1):  Cars
matchObj.group(2):  smarter

进程已结束,退出代码0

"(www)(cnblogs)(com)"