Python常用正则表达式使用汇总

下面列出Python正则表达式的几种匹配用法,具体内容如下所示:

此外,关于正则的一切http://deerchao.net/tutorials/regex/regex.htm

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)

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