【python 正则表达式：太复杂了所以通过练习-2(邮箱-IP地址)】编写常见格式的字符串的正则表达式来由浅入深的认识它

import re
def match_email(string):
    pattern = r"^[a-zA-Z0-9_]+@[a-zA-Z0-9]+\.[a-zA-Z0-9]+$"
    match = re.match(pattern, string)
    if match:
        return True
    else:
        return False
string = "abc@example.com"
print(match_email(string)) # True
string = "user_123@example.co.uk"
print(match_email(string)) # True
string = "info@domain.com.cn"
print(match_email(string)) # True

import re

def match_ip_address(string):
    pattern = r"^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$"
    match = re.match(pattern, string)
    if match:
        return True
    else:
        return False
string = "192.168.0.1"
print(match_ip_address(string))  # True
string = "172.16.58.3"
print(match_ip_address(string))  # True
string = "255.255.255.255"
print(match_ip_address(string))  # True