Python正则表达式的几种匹配用法
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)