Regular Expressions 101

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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

/
/
gmi

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"(\B(\?\?|\?)|\B(\!\!|\!)|\B(\[\])|\b(RWC)|\b(TODO))[:;.,-]?\d*($|\s.*$|\(.*$)" test_str = ("# Oh yeah, good luck with that.\n" "?? Can I use the gun?\n\n" "Enough about your promiscuous mother, Hermes! We have bigger problems. \n\n" "!!- Guards! Bring me the forms I need to fill out to have her taken away! \n\n" "TODO Shinier than yours, meatbag. \n\n" "- Wow, you got that off the Internet? \n" "- In my day, the Internet was only used to download pornography.\n\n" "Would you censor the Venus de Venus just because you can see her spewers? \n" "! No argument here. \n\n" "RWC: Oh no! The professor will hit me! \n" "[] But if Zoidberg 'fixes' it… then perhaps gifts! \n\n" "I was all of history's great robot actors - Acting Unit 0. 8; Thespomat; David Duchovny!\n\n" "[] Five hours? Aw, man! Couldn't you just get me the death penalty?\n\n" "When I was first asked to make a film about my nephew, Hubert Farnsworth, I thought \"Why should I?\" Then later, Leela made the film. But if I did make it, you can bet there would have been more topless women on motorcycles. Roll film! Um, is this the boring, peaceful kind of taking to the streets?\n") matches = re.finditer(regex, test_str, re.MULTILINE | re.IGNORECASE) 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