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"^(?:(?=([\s\S]+?(?=\nX:|$)))\1){2}" test_str = ("T:Broken Pledge, The R:reel D:De Dannan: Selected Reels and Jigs. Z:Also played in Edor, see #734 Z:id:hn-reel-56 M:C| K:Ddor dcAG ADDB|cAGF ECCE|D2 (3EFG Addc|AcGc Aefe| dcAG FGAB|c2Bd cAGE|D2 (3EFG AddB|cAGE FDD2:| |:dcAG Acde|~f3d ecAB|cAGE GAcd|ec~c2 eage| dcAG Acde|fedf ecAG|~F3G AddB|cAGE FDD2:| P:\"Variations:\" |:dcAG ~A3B|cAGF ECCE|DEFG Addc|(3ABc Gc Aefe| dcAG FGAB|c2Bd cAGE|DEFG AddB|A2GE FDD2:| |:dcAG Acde|~f3d ecAB|cAGE GAcd|ec~c2 eage| dcAG Acde|~f3d ecAG|FEFG AddB|A2GE FDD2:| \n" "X:2 T:Broken Pledge, The M:C L:1/8 Q:250 K:D dcAG A2 dB | cAGF EDC2 | DEFG Ad ~d2 | AcGc Adfe | dcAG A2 dB | cAGF EDC2 | DEFG Ad ~d2 | AcGc ADD2 :| |: dcAG A2 de | fedf edAB | cAGE GAcd | ec ~c2 eage | dcAG A2 de | fedf edcA | F3 E FGAB | cAGE {F}ED D2 :|| 2021-09-17T18:55:34.779Z c2977fd7-2057-44cc-bdf3-7f4243a53e33\n" "X:2 T:Broken Pledge, The M:C L:1/8 Q:250 K:D dcAG A2 dB | cAGF EDC2 | DEFG Ad ~d2 | AcGc Adfe | dcAG A2 dB | cAGF EDC2 | DEFG Ad ~d2 | AcGc ADD2 :| |: dcAG A2 de | fedf edAB | cAGE GAcd | ec ~c2 eage | dcAG A2 de | fedf edcA | F3 E FGAB | cAGE {F}ED D2 :|| 2021-09-17T18:55:34.779Z c2977fd7-2057-44cc-bdf3-7f4243a53e33 ") 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