Python正则表达式的几种匹配用法

时间:2024-02-19 09:18:32

下面列出Python正则表达式的几种匹配用法:

1.测试正则表达式是否匹配字符串的全部或部分

regex=ur"" #正则表达式
if re.search(regex, subject):
    do_something()
else:
    do_anotherthing()

 

2.测试正则表达式是否匹配整个字符串

 

regex=ur"/Z" #正则表达式末尾以/Z结束
if re.match(regex, subject):
    do_something()
else:
    do_anotherthing()

 

3.创建一个匹配对象,然后通过该对象获得匹配细节(Create an object with details about how the regex matches (part of) a string)

 

regex=ur"" #正则表达式
match = re.search(regex, subject)
if match:
    # match start: match.start()
    # match end (exclusive): atch.end()
    # matched text: match.group()
    do_something()
else:
    do_anotherthing()

 

4.获取正则表达式所匹配的子串(Get the part of a string matched by the regex)

 

regex=ur"" #正则表达式
match = re.search(regex, subject)
if match:
    result = match.group()
else:
    result = ""

 

5. 获取捕获组所匹配的子串(Get the part of a string matched by a capturing group)

 

regex=ur"" #正则表达式
match = re.search(regex, subject)
if match:
    result = match.group(1)
else:
    result = ""

 

6. 获取有名组所匹配的子串(Get the part of a string matched by a named group)

 

regex=ur"" #正则表达式
match = re.search(regex, subject)
if match:
    result = match.group"groupname")
else:
    result = ""

 

7. 将字符串中所有匹配的子串放入数组中(Get an array of all regex matches in a string)

 

result = re.findall(regex, subject)

 

8.遍历所有匹配的子串(Iterate over all matches in a string)

 

for match in re.finditer(r"<(.*?)/s*.*?//1>", subject)
    # match start: match.start()
    # match end (exclusive): atch.end()
    # matched text: match.group()

 

9.通过正则表达式字符串创建一个正则表达式对象(Create an object to use the same regex for many operations)

 

reobj = re.compile(regex)

 

10.用法1的正则表达式对象版本(use regex object for if/else branch whether (part of) a string can be matched)

 

reobj = re.compile(regex)
if reobj.search(subject):
    do_something()
else:
    do_anotherthing()

 

11.用法2的正则表达式对象版本(use regex object for if/else branch whether a string can be matched entirely)

 

reobj = re.compile(r"/Z") #正则表达式末尾以/Z 结束
if reobj.match(subject):
    do_something()
else:
    do_anotherthing()

 

12.创建一个正则表达式对象,然后通过该对象获得匹配细节(Create an object with details about how the regex object matches (part of) a string)

 

reobj = re.compile(regex)
match = reobj.search(subject)
if match:
    # match start: match.start()
    # match end (exclusive): atch.end()
    # matched text: match.group()
    do_something()
else:
    do_anotherthing()

 

13.用正则表达式对象获取匹配子串(Use regex object to get the part of a string matched by the regex)

 

reobj = re.compile(regex)
match = reobj.search(subject)
if match:
    result = match.group()
else:
    result = ""

 

14.用正则表达式对象获取捕获组所匹配的子串(Use regex object to get the part of a string matched by a capturing group)

 

reobj = re.compile(regex)
match = reobj.search(subject)
if match:
    result = match.group(1)
else:
    result = ""

 

15.用正则表达式对象获取有名组所匹配的子串(Use regex object to get the part of a string matched by a named group)

 

reobj = re.compile(regex)
match = reobj.search(subject)
if match:
    result = match.group("groupname")
else:
    result = ""

 

16.用正则表达式对象获取所有匹配子串并放入数组(Use regex object to get an array of all regex matches in a string)

 

reobj = re.compile(regex)
result = reobj.findall(subject)

 

17.通过正则表达式对象遍历所有匹配子串(Use regex object to iterate over all matches in a string)

 

reobj = re.compile(regex)
for match in reobj.finditer(subject):
    # match start: match.start()
    # match end (exclusive): match.end()
    # matched text: match.group()

字符串替换

 

1.替换所有匹配的子串

 

#用newstring替换subject中所有与正则表达式regex匹配的子串
result = re.sub(regex, newstring, subject)

 

2.替换所有匹配的子串(使用正则表达式对象)

 

reobj = re.compile(regex)
result = reobj.sub(newstring, subject)

 

字符串拆分

 

1.字符串拆分

 

result = re.split(regex, subject)

 

2.字符串拆分(使用正则表示式对象)

 

reobj = re.compile(regex)
result = reobj.split(subject)