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

/
/
g

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".*Version (\S+)" test_str = ("//Version 1.0 Aug 31st 2011 -First Release.\n" "//Version 1.1 Sep 29th 2011 \n" "//Bug fixed: When using hovercard in hovercard, the inner hovercard shows up as well when parent hovercard opens.\n" "//\n" "//Version 1.2 Sep 30th 2011\n" "//Enhancement: The hovercard now adjust (either open on left or right) in accordance to the view port.\n" "//Added options:\n" "//openOnLeft: force hovercard to open on left. (eg: if the hovered name appear in the end of sentence)\n" "//\n" "//Version 2.0 Nov 8th 2011\n" "//Bug Fixes: zindex issue.\n" "//Enhancements: Supercool built in social profile cards like Twitter and Facebook!\n" "//Added options:\n" "//showTwitterCard: displays a built in twitter card format for a twitter screenname. Maximum 150 twitter lookup per hour.\n" "//twitterScreenName: twitter screen name for the hovercard. If no username/screenname is provided, hovercard attempts to look up for hovered text.\n" "//showFacebookCard: displays a built in facebook card format for a facebook username/pages/events etc. Works best with Facebook pages.\n" "//facebookUserName: facebook username/pages/events/groups for the hovercard. If no username is provided, hovercard attempts to look up for hovered text.\n" "//\n" "//Version 2.1 Nov 22nd 2011\n" "//Enhancement: attribute 'data-hovercard'. You may now use data-hovercard attribute with your label/link etc to set the twitter or facebook usernames.\n" "//Added options:\n" "//showCustomCard: You may now add your own custom data source and display the profile data using existing card format.\n" "//\n" "//Version 2.2 Dec 9th 2011\n" "//Bug Fixes: zindex issue with IE7.\n" "//\n" "//Version 2.3 Dec 15th 2011\n" "//Enhancement: The plugin now auto adjust on the edges of visible window/viewport!\n" "//Added options:\n" "//openOnTop: Set 'openOnTop' to true if you want the hovercard to always open on left.\n" "//customCardJSON: Provide a local json data with showCustomCard. Inherits plugin's social card format/styles.\n" "//delay: Delay the hovercard appearance on hover.\n" "//\n" "//Version 2.4 Apr 12th 2012\n" "//Added options:\n" "//autoAdjust: The plugin's default functionality to auto adjust to the viewport ") matches = re.finditer(regex, test_str) 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