python regular expression match example

The regular itself is a language:The regular expression uses a single string to describe, match a series of strings that conform to a certain syntactic rule, is very powerful in text processing, and is often used as a crawler to crawl specific content, and Python itself does

' verb ', but cannot match ' er ' in ' Never '. \ n, \ t, et. Matches a line break. Matches a tab character. such as \1...\9 Matches the contents of the nth grouping. \10 Matches the contents of the nth grouping, if it is matched. Otherwise, it refers to an expression of octal character code. Modifier modifier Descriptio

This article uses two examples to compare and analyze the similarities and differences between using regular expressions to match a tag in js and c #. Let's take a look at it for your reference, which is helpful for a deep understanding of the use of regular expressions. Not much nonsense, all in the code, directly on JS Code: The Code is as follows:

that uses regular expressions to match IP addresses and convert IP addresses to corresponding values:Function IP2V (ip){Re =/(\ d +) \. (\ d +)/g // Regular Expression matching IP addressesIf (re. test (ip )){Return RegExp. $1 * Math. pow (255) + RegExp. $2 * Math. pow () + RegExp. $3 * + RegExp. $4*1}Else{Throw new E

-Numeric \w Match non-alphanumeric numbers \s Matches any whitespace character, equivalent to [\t\n\r\f]. \s Match any non-null character \d Match any number, equivalent to [0-9]. \d Match any non-numeric \a

digit (because it follows the last expression, it must contain uppercase/lowercase letters, numbers, or special character sets [.. **************************************** *************************************** // Check user name: only 1-30 strings starting with letters can be entered /^ [A-Za-Z] {1, 30} $/ **************************************** *************************************** // Password verification: only 6-20 letters, numbers, and under

escape Function of the Python Regular Expression module is independent. For example, to match a backslash character, you must write the parameter :'\\\\': Python escapes the string \\\\ \\The re module obtains the passed \ and in

Python regular expression,Python Regular Expression learning Summary: 1. First, we recommend the Learning Website: Cainiao learning: http://www.runoob.com/python/

use '(? : '') ', Instead of just a pair of parentheses, it will produce an absolutely unexpected result. For example, match the repeated 'AB' in the string' >>> S = 'ababab abbabb aabaab' >>> Re. findall (R' \ B (? : AB) + \ B ', S) ['Ababab'] If you only use a pair of parentheses, see what the result will be: >>> Re. findall (R' \ B (AB) + \ B ', S) ['AB'] This is because if only one pair

1. Regular expressions?? Regular expressions provide the basis for advanced text pattern matching, extraction, and/or textual search and replace functions, and simply, regular expressions are strings of characters and special symbols. Python supports regular expressions thro

(' world$ ', re. I) If R2.search (' helloworld\n '): print ' Search succeeds ' Else print ' Search fails ' Example: calling Directly If Re.search (R ' ABC ', ' Helloaaabcdworldn '): print ' Search succeeds ' Else print ' Search fails ' SplitRe.split (Pattern, string[, maxsplit=0, flags=0])Split (string[, maxsplit=0])Function: The part of a string matching regula