Python中正则表达式的用法实例汇总
正则表达式是Python程序设计中非常实用的功能，本文就常用的正则表达式做一汇总，供大家参考之用。具体如下：
一、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, number = re.subn(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, number = reobj.subn(newstring, subject)
二、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)
三、匹配
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
regex=ur"..." #正则表达式 match = re.search(regex, subject) if match: # match start: match.start() # match end (exclusive): match.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): match.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): match.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()
感兴趣的读者可以动手调试一下本文实例代码，相信会有新的收获。
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
PHP and Python: Different Paradigms Explained
Apr 18, 2025 am 12:26 AM
PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.
Choosing Between PHP and Python: A Guide
Apr 18, 2025 am 12:24 AM
PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.
Python vs. JavaScript: The Learning Curve and Ease of Use
Apr 16, 2025 am 12:12 AM
Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.
PHP and Python: A Deep Dive into Their History
Apr 18, 2025 am 12:25 AM
PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.
Can vs code run in Windows 8
Apr 15, 2025 pm 07:24 PM
VS Code can run on Windows 8, but the experience may not be great. First make sure the system has been updated to the latest patch, then download the VS Code installation package that matches the system architecture and install it as prompted. After installation, be aware that some extensions may be incompatible with Windows 8 and need to look for alternative extensions or use newer Windows systems in a virtual machine. Install the necessary extensions to check whether they work properly. Although VS Code is feasible on Windows 8, it is recommended to upgrade to a newer Windows system for a better development experience and security.
Can visual studio code be used in python
Apr 15, 2025 pm 08:18 PM
VS Code can be used to write Python and provides many features that make it an ideal tool for developing Python applications. It allows users to: install Python extensions to get functions such as code completion, syntax highlighting, and debugging. Use the debugger to track code step by step, find and fix errors. Integrate Git for version control. Use code formatting tools to maintain code consistency. Use the Linting tool to spot potential problems ahead of time.
How to run python with notepad
Apr 16, 2025 pm 07:33 PM
Running Python code in Notepad requires the Python executable and NppExec plug-in to be installed. After installing Python and adding PATH to it, configure the command "python" and the parameter "{CURRENT_DIRECTORY}{FILE_NAME}" in the NppExec plug-in to run Python code in Notepad through the shortcut key "F6".
Is the vscode extension malicious?
Apr 15, 2025 pm 07:57 PM
VS Code extensions pose malicious risks, such as hiding malicious code, exploiting vulnerabilities, and masturbating as legitimate extensions. Methods to identify malicious extensions include: checking publishers, reading comments, checking code, and installing with caution. Security measures also include: security awareness, good habits, regular updates and antivirus software.
