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
Processing...

Test String

Code Generator

Language

Generated Code

import re regex = re.compile(r"\b(?<=[A-Z]{2} [–-] ).*?\b[Cc]hapter\b") test_str = ("Match unknown number of words that lies between two known patterns\n\n" "I'm looking to make a regex for use in LibreOffice Writer's \"Find and Replace\" function. LibreOffice version 25.8.4.2. \n\n" "The text I want to search looks like the following.\n\n" "008 – San Terremoto CA | 010 - Eastern AK – Joe Jolson Chapter | 011 - Doughtown NY | 012 - Copperville AZ | 014 - Gatorville FL | 015 - Swamptown FL | 018 - District of Columbia (DC) | 019 - Central PA | 041 – Stoddard Mill MA - Cpl Mike G. Paulson Chapter |139 - North Pacific Bay WA |\n\n\n\n" "1. Most of the records end with \n\n" "a two-letter U.S. state abbreviation, a space, and a pipe. \n\n" "2. A number of records end with\n\n" "a two-letter U.S. state abbreviation, a space, a hyphen, a space, unknown number of words separated by spaces, final space, the word \"chapter\", space, pipe.\n\n" "\"Chapter\" may or may not be capitalized.\n\n" "In records which match the description in \"2.\" above, I want to match any text which follows the two-letter state abbreviation with a name and the word \"chapter\". Examples of that text is in boldface type above.\n\n" "I tried a number of things, lastly this:\n\n" "(?<=\\[A-Z\\]{2})\\\\s-\\\\s\\[\\\\w\\]+\\\\s\\[Chapter|chapter\\]\n\n" "and\n\n" "(?<=\\[A-Z\\]{2})\\\\s-\\\\s\\[a-zA-Z\\]+\\\\s\\[Chapter|chapter\\]\n\n" "It has not yet worked.\n\n" "I welcome suggestions. Thank you") matches = regex.finditer(test_str) for match_num, match in enumerate(matches, start=1): print(f"Match {match_num} was found at {match.start()}-{match.end()}: {match.group()}") for group_num, group in enumerate(match.groups(), start=1): print(f"Group {group_num} found at {match.start(group_num)}-{match.end(group_num)}: {group}")

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