Python Basics-Regular 1

What is a regular expression?

A regular expression is a small, highly specialized, language that is used primarily for string processing

Regular expressions are a common language, implemented in Python via the RE module, and the import re

Tools: on-line regular expression testing

http://tool.oschina.net/regex/

Http://www.jb51.net/shouce/jquery1.82/regexp.html

Character match-Normal character

Most characters match themselves exactly. The expression shit matches the string "shit" exactly

Character match-Meta character

^ Match beginning of Line

$ Match Line End

* Match the previous character by more than or equal to 0 times

? Matches the previous character 0 or 1 times to indicate whether a

+ Match the previous character by more than or equal to 1 times

. Match single character

[] Specify a character set [ABC]; [A-z]; [1-9];　　[A-za-z0-9] (or a relationship, such as [ABC] indicates the presence of a or B or c other similar)

In addition, you can match characters that are not in the interval range [^5], where you must use []

\ transfer metacharacters to normal characters \ \, \^, \[

Eg: want to match the number in the string (ONE1TWO2THREE3FOUR4)

Regular:/d

{} Number of repetitions

What does eg:a{4} mean?

Match AAAA

| Represents or, X|y represents a match for x or Y

() grouping

eg

Regular: C|d, match string "ABCD", result?

Cd

Regular: (AB), match string "ABC ADC ABB", result?

Explanation: AB whole goes to match string

AB AB

Summarize:

　　

Practice:

data [' AD123453 ', ' AC345466 ', ' AR695235 '], matching 2 uppercase letters and 6 digits

\W{2}\D{6} \w+\d+ [A-z]{2}[0-9]{6}

Match the domestic mobile phone number

Features: All numbers

Opening 1X

Length 11

^ (13|15|18) [0-9]{9}

Python Basics-Regular 1