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

/
/
gmx

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* (?<host>[\w-\.]*) \s* (?<rectype>\w*) \s* (?<value>[\w\.-].*) \s*$ ) """ test_str = ("> ls -d midlandls.pncint.net \n" "[pasum60ad02.pncint.net]\n" " midlandls.pncint.net. SOA vasan60ad03.pncint.net ip.address.request.pncbank.com. (562550790 10800 3600 1209600 60)\n" " midlandls.pncint.net. NS vaash60ad04.pncint.net \n" " midlandls.pncint.net. NS pasum60ad11.pncint.net \n" " midlandls.pncint.net. NS pasum60ad01.pncint.net \n" " midlandls.pncint.net. NS pasum60ad02.pncint.net \n" " arcs-msmq CNAME weka357w.prod.pncint.net\n" " bar-rpt CNAME wbar303a.prod.pncint.net\n" " Bin CNAME services-gf2.midlandls.pncint.net\n" " cigna-msmq CNAME welm350w.prod.pncint.net\n" " citigroup-msmq CNAME welm352w.prod.pncint.net\n" " Cwm CNAME services-gf2.midlandls.pncint.net\n" " Cwm-app CNAME services-gf2.midlandls.pncint.net\n" " cwm-rpt CNAME wcwm316a.prod.pncint.net\n" " dbank-msmq CNAME welm344w.prod.pncint.net\n" " egs CNAME egs-gf0.midlandls.pncint.net\n" " egs-gf0 A 10.15.5.238\n" " egs-gf1 A 10.38.5.238\n" " egs-snat-gf0 A 10.15.7.238\n" " egs-snat-gf1 A 10.38.7.238\n" " eka CNAME services-gf2.midlandls.pncint.net\n" " elm CNAME services-gf2.midlandls.pncint.net\n" " fdic-msmq CNAME welm358w.prod.pncint.net\n" " genworth-msmq CNAME welm365w.prod.pncint.net\n" " icsg-msmq CNAME welm375w.prod.pncint.net\n" " iru CNAME services-gf2.midlandls.pncint.net\n" " iru-rpt CNAME wiru307a.prod.pncint.net\n" " mat CNAME services-gf2.midlandls.pncint.net\n" " mat-app CNAME services-gf2.midlandls.pncint.net\n" " mat-rpt CNAME wmat302a.prod.pncint.net\n" " mde CNAME services-gf2.midlandls.pncint.net\n" " mde-internet CNAME services-gf2.midlandls.pncint.net\n" " mfn CNAME services-gf2.midlandls.pncint.net\n" " mfn-app CNAME services-gf2.midlandls.pncint.net\n" " mfn-rpt CNAME wmfn318a.prod.pncint.net\n" " mis CNAME services-gf2.midlandls.pncint.net\n" " mis-app CNAME services-gf2.midlandls.pncint.net\n" " mis-rpt CNAME wmis308a.prod.pncint.net\n" " mls-msmq CNAME weka353w.prod.pncint.net\n" " mvm CNAME services-gf1.midlandls.pncint.net\n" " mvm-rpt CNAME wmvm302a.prod.pncint.net\n" " pii CNAME services-gf2.midlandls.pncint.net\n" " pnc-msmq CNAME weka373w.prod.pncint.net\n" " pnclms-msmq CNAME weka349w.prod.pncint.net\n" " rdt CNAME services-gf1.midlandls.pncint.net\n" " services-gf1 A 10.26.64.229\n" " services-gf2 A 10.28.8.229\n" " services-snat-gf1 A 10.26.68.249\n" " services-snat-gf2 A 10.28.12.227\n" " wdunlop-msmq CNAME welm31bw.prod.pncint.net\n" " wlm CNAME services-gf2.midlandls.pncint.net\n" " wlm-app CNAME wwlm305w.prod.pncint.net\n" " wlm-rpt CNAME wwlm306a.prod.pncint.net\n" " midlandls.pncint.net. SOA vasan60ad03.pncint.net ip.address.request.pncbank.com. (562550790 10800 3600 1209600 60)\n") matches = re.finditer(regex, test_str, re.MULTILINE | re.VERBOSE) 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