Python正则表达式使用经典实例

大家快瞧那结冰的湖水,春风一吹冰都融化了,河里的小鱼都游出海面,在湖水中自由的游来游去,多可爱的小鱼啊!多么欢快的小鱼啊!真是让人深深的为它那可爱的摸样着迷。春风一吹过那枯黄的小草身边时,小草突然边了摸样,它从原来的枯黄变成了嫩绿,慢慢地小草从嫩绿变成了鲜绿渐渐地越变越绿,绿的让人难以相信那是小草。啊!小草我为你的样子感到是个奇迹。

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)

到此这篇关于Python正则表达式使用经典实例就介绍到这了。成功不会向我们走来,我们必须走向胜利;智慧不会向我们走来,我们必须勤奋思索;快乐不会向我们走来,我们必须用心体验。更多相关Python正则表达式使用经典实例内容请查看相关栏目,小编编辑不易,再次感谢大家的支持!

您可能有感兴趣的文章
python 正则表达式如何实现重叠匹配

Python爬虫好代码教程之利用正则表达式匹配网页内容

Python字符串和正则表达式中的反斜杠('\')问题详解

Python爬虫运用正则表达式的方法和优缺点

Python 正则表达式 re.match/re.search/re.sub的使用解析