正则表达式匹配开头和结尾（^ $ [^指定字符]）

1. 匹配开头和结尾

示例1：^

需求：匹配以数字开头的数据

import re# 匹配以数字开头的数据match_obj = re.match("^\d.*", "1hello_world!")print(match_obj)if match_obj:# 获取匹配结果print(match_obj.group())else:print("匹配失败")match_obj2 = re.match("^\d.*", "hello_world!")print(match_obj2)if match_obj2:# 获取匹配结果print(match_obj2.group())else:print("匹配失败")

运行结果:

示例2：$

需求: 匹配以数字结尾的数据

import re# 匹配以数字结尾的数据match_obj = re.match(".*\d$", "hello_world5")print(match_obj)if match_obj:# 获取匹配结果print(match_obj.group())else:print("匹配失败")match_obj2 = re.match(".*\d$", "hello_world")print(match_obj2)if match_obj2:# 获取匹配结果print(match_obj2.group())else:print("匹配失败")

运行结果：

示例3：^ 和 $

需求: 匹配以数字开头，中间内容不管，以数字结尾

import rematch_obj = re.match("^\d.*\d$", "4hello_world4")print(match_obj)if match_obj:# 获取匹配结果print(match_obj.group())else:print("匹配失败")

运行结果:

2.除了指定字符以外都匹配

[^指定字符]: 表示除了指定字符都匹配

需求: 第一个字符除了aeiou的字符都匹配

import rematch_obj = re.match("[^abc]", "ILoveChina")if match_obj:# 获取匹配结果print(match_obj.group())else:print("匹配失败")match_obj2 = re.match("[^abc]", "aaa")if match_obj2:# 获取匹配结果print(match_obj2.group())else:print("匹配失败")match_obj3 = re.match("[^abc].*", "China")if match_obj3:# 获取匹配结果print(match_obj3.group())else:print("匹配失败")match_obj4 = re.match("[^abc]*", "China")if match_obj4:# 获取匹配结果print(match_obj4.group())else:print("匹配失败")

执行结果：