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

/
/
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"Abstract title:(?:.|\r?\n\w)*" test_str = ("Prof. Imperdiet montes, metus elementum eleifend eget eget adipiscing augue.\n" "Abstract title: Lorem ipsum dolor sit amet, consectetuer adipiscing\n\n" "A, nec, quam eleifend quis, magnis sit pretium. leo augue. amet, elit. vel\n\n" "Vel, dis eget nascetur justo. imperdiet consequat et sit Nam Aenean a, Quisque\n" "Enim. a, dui. Aenean lorem Phasellus commodo quis, pretium ultricies nascetur\n" "tincidunt. sem. vitae,\n" "montes, tellus. amet, venenatis natoque enim. fringilla\n" "quis, vitae, Aenean Etiam viverra ipsum dapibus ut elementum Aenean Lorem eget,\n" "nisi mollis Curabitur Quisque Aenean rhoncus sociis justo, sem. justo, vel\n" "Aenean ultricies nec, eu laoreet.\n\n" "Dr. Enim. vitae, feugiat in, Aenean\n" "Abstract title: Massa. sociis dis dapibus dolor semper ipsum\n" "jalor\n\n" "Semper tincidunt. ullamcorper commodo magnis viverra pede elit. eget aliquet\n" "eleifend vel, eleifend feugiat pede Vivamus ridiculus vitae, a, ligula, et Nulla\n" "ligula vulputate ac, nisi. enim dapibus. Donec metus In sit dolor Nam ultricies\n" "imperdiet. pellentesque Cras eu, massa quis porttitor parturient varius ut,\n" "Phasellus arcu. pretium. quam augue. eu, adipiscing felis, enim. ante,\n" "vulputate Integer dui. ultricies a, dictum rutrum. Nullam nec, quis,\n" "consequat Cum tellus. dis felis dolor. nulla Aliquam Donec massa. justo. in,\n" "nascetur\n" "Semper tincidunt. ullamcorper commodo magnis viverra pede elit. eget aliquet\n" "eleifend vel, eleifend feugiat pede Vivamus ridiculus vitae, a, ligula, et Nulla\n\n\n" "Dr. Justo. nisi elementum ante, Donec Aenean Nulla\n" "Abstract title:\n\n" "Aenean consectetuer leo penatibus eget imperdiet nisi. consequat\n" "lorem pretium mus. \n\n" "Prof. Dr. Aliquam metus semper\n" "Abstract title: Aliquet augue. amet, enim ut justo, nec, eleifend lorem enim. nisi. ipsum\n" "eleifend\n" "More information will be available soon.") 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