正则贪婪与非贪婪模式简单实现

   　　正则模式根据特殊字符组成，可以在一长串字符串中获取匹配我们想要的数据

line = "bobby123"
regex_str = "^b.*3$"#^以b字符开头，3结尾
if re.match(regex_str, line):
    print("yes")
else:
    print("no")

　　贪婪模式想着尽可能多地去匹配满足自身条件的字符

# =========贪婪匹配====================
# 从右边开始匹配
line = "boddddddddddddddddddddddddbby123"
regex_str = ".*(b.*b).*"  # .*贪婪匹配尽可能多地占用匹配字符
match_obj = re.match(regex_str, line)
print(match_obj.group(1)) #bb

　　非贪婪模式通过加 “?”匹配字符的限制，尽可能少地去匹配满足自身条件的字符，容易满足自身要求

# =========非贪婪匹配====================
# 从左边开始匹配
line = "boddddddddddddddddddddddddbby123"
regex_str = ".*?(b.*?b).*"  # .*非贪婪匹配尽可能少地占用匹配字符
match_obj = re.match(regex_str, line)
print(match_obj.group(1))  # boddddddddddddddddddddddddb