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

Substitution
Processing...

Code Generator

Language

Generated Code

import re regex = re.compile(r"^(0|[1-9]+[0-9]*) (@[^@]+@ |)([A-Za-z0-9_]+)( [^\n\r]*|)$", flags=re.MULTILINE) test_str = ("0 @N1@ NOTE Lorem ipsum dolor sit amet\n" "0 HEAD\n" "1 SOUR FTM\n" "2 VERS 22.2.6.950\n" "1 DEST FTM\n" "1 DATE 31 MAR 2017\n" "1 CHAR UTF-8\n" "3 _LINK http://www.facebook.com/1247584965\n" "2 SOUR @S122@\n" "3 PAGE Facebook update - David Hatch - 6/5/2013\n" "3 _LINK http://www.facebook.com/1247584965\n\n\n" "1 RESI\n" "2 DATE BET 1935 AND 1993\n" "2 PLAC San Francisco, California, USA\n" "1 RESI\n" "2 DATE 1994\n" "2 PLAC San Francisco, California, USA\n" "2 SOUR @S605@\n" "3 DATA\n" "4 TEXT Birth date: 20 Sep 1966 Birth place: Residence date: 1994 \n" "5 CONC Residence place: San Francisco, CA\n" "1 RESI 106 Oakcrest Rd\n" "2 DATE 26 MAR 2017\n" "2 PLAC San Anselmo, Marin, California, USA\n" "1 FAMS @F500@\n" "1 FAMC @F656@\n" "0 @I923@ INDI\n" "1 NAME Vincent /Crilley/\n" "1 SEX M\n" "1 FAMS @F254@\n" "0 @I5899@ INDI\n" "1 NAME Marjorie Edna /Footitt/\n" "2 SOUR @S506@\n" "2 SOUR @S176@\n" "2 SOUR @S168@\n" "2 SOUR @S624@\n" "3 DATA\n" "4 TEXT Residence date: Residence place: USA\n" "2 SOUR @S115@\n" "3 PAGE Year: 1940; Census Place: St Paul, Ramsey, Minnesota; Roll: T627_1996; \n" "4 CONC Page: 11A; Enumeration District: 90-73.\n" "3 DATA\n" "4 _TEXT Birth date: abt 1918 Birth place: North Dakota Residence date: 1 \n" "5 CONC Apr 1940 Residence place: St Paul, Ramsey, Minnesota, United States\n" "2 SOUR @S607@\n" "3 PAGE Year: 1920; Census Place: Carrington, Foster, North Dakota; Roll: \n" "4 CONC T625_1334; Page: 13B; Enumeration District: 117; Image: .\n" "3 DATA") subst = "\\n2($2) 3($3) 4($4) 5($5) 6($6) 7($7) \\n\\n8($8) 9($9) 10($10) 11($11) 12($12) 13($13) 14($14) 15($15) 16($16) 18($18) 20($20) 21($21)\\n\\n\\n\\n" result = regex.sub(subst, test_str) if result: print(result)

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