Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

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
No Match

/
/
gm

Test String

Code Generator

Language

Generated Code

# coding=utf8 # the above tag defines encoding for this document and is for Python 2.x compatibility import re regex = r"^(?:.*[\/\\])?(?<FileNameWithoutExtension>.*)\.(.*?(?=\#|\?|$))" test_str = ("http://www.cultureandcosmos.org/pdfs/2-2/Voss_Music_Spheres.pdf#456\n\n" "https://static1.squarespace.com/static/58d6b5ff86e6c087a92f8f89/t/5913df9915cf7db9454ad94a/1494474655305/Plato_and_Hesiod.pdf#page=270\n\n" "http://www.cultureandcosmos.org/pdfs/2-2/Voss_Music_Spheres.pdf?power=222p#11\n\n" "https://archive.flossmanuals.net/inkscape/_booki/inkscape/inkscape.pdf\n\n\n" "Taylor Swift - New Romantics.m4a\n" "YT/Subto2mp3/Taylor Swift - New Terribly Romantics.m4a\n" "Grow - Conan Blue (Official Video) has already been recorded in archive.m4a\n" "PowerOptim Iol/Techno/(Official Video) Blue Burrow was already been recorded in archive - Bak.wm4\n" "/Great Bun/Output Files/çè/Grow - Conan DARK (Official AUDIO) has already been recorded in archive.m4b\n" "Matter Oil_9999.zip\n" "Qpl$-pol.hrlp/perm.ui.pol/i op/doesn't matter.mp4\n" "Small Laser4.m4a\n" "manicur pliu/love is in the a°°_II+?§@R.txt\n" "^Level09\\\\Power Pol\\energy.m4a\n" "lollller_blllade 1987 (c)/super €/music_piece_.mp3\n" "\\.\\.$./../../loli( u1990) _98.lop.pl/fil l/fill2asm.aile.asm.gz.zip\n" "/Taylor Swift - New Romantics._m4a\n" "\\$/Subto2/mp3/Taylor Swift -&- New Romantics.m4a\n" "/Grow - Conan Gray (Official Video) has already been recorded in archive.m4a\n" "C:\\PowerOptim Iol/Grow - The New Gray (Official Video) has been recorded [<1999>.wm4\n" "/Great Bun/Output Files/çè/Grow - WiLlL(O)W Gray \"unofficial\" video has not been recorded in archive.m4b\n" "/Matter Oil_9999.zip\n" "file:///Qpl$-pol.hrlp/perm.ui.pol/i op/matter.mp4\n" "/£¥«^6<4>à_»Laser4 ``[12{2%}32]deg`‘.webm\n" "manicur pliu/great.power.great.responsibility?.gz.tar.zip\n" "./poi kiol/greater.power.greater.responsibility!.gz.tar.zip\n" "^Level09\\Power Pol\\energy.m4a\n" "lollller_blllade 1987 (c)/super €/music_piece_.mp3\n" "/The 'great' solitude of zorro #12/the 退ellent urge_for.mo.tar.gz\n\n\n\n\n") matches = re.finditer(regex, test_str, re.MULTILINE) for matchNum, match in enumerate(matches, start=1): print ("Match {matchNum} was found at {start}-{end}: {match}".format(matchNum = matchNum, start = match.start(), end = match.end(), match = match.group())) for groupNum in range(0, len(match.groups())): groupNum = groupNum + 1 print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = match.start(groupNum), end = match.end(groupNum), group = match.group(groupNum))) # Note: for Python 2.7 compatibility, use ur"" to prefix the regex and u"" to prefix the test string and substitution.

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