1、ASCII字符对应的字符组 [\x00-\x7F]

例如：判断是否是ASCII字符

# -*- coding: UTF-8 -*-
import re

print (re.search("^[\x00-\x7F]$","c")!=None)
print (re.search("^[\x00-\x7F]$","I")!=None)
print (re.search("^[\x00-\x7F]$","0")!=None)
print (re.search("^[\x00-\x7F]$","<")!=None)
print (re.search("^[\x00-\x7F]$","@")!=None)
 

2、正则表达式的提取，以python代码为例

#正则表达式的提取
print (re.search("^[\x00-\x7F]$","@").group(0))

#匹配并提取所有的字符串,r 代表原生字符
for zipcode in re.findall(r"\d{6}","zipcode1:201203,zipcode2:100859"):
    print (zipcode)