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"ssl_subject\=\"(CN=(?<CN>[^=]*))?(C=(?<C>[^=]*))?(S=(?<S>[^=]*))?(O=(?<O>[^=]*))?(OU=(?<OU>[^=]*))?\" ssl_start_time" test_str = ("ssl_issuer=\"CN=DigiCert SHA2 High Assurance Server CA C=US O=DigiCert Inc OU=www.digicert.com\" ssl_hash=\"f41565b049f039e765a0f8be8271a4b4817b7378\" ssl_subject=\"CN=syndication.twitter.com C=US S=California O=Twitter, Inc. OU=Twitter Security\" ssl_start_time=\"Wed Jun 29 00:00:00 2016 UTC\" ssl_end_time=\"Mon Sep 16 12:00:00 2019 UTC\" ssl_type=\"X.509 Certificate\" ssl_extended_key_usage=\"Server Authentication, Client Authentication\" ssl_key_length=\"2048 bits\" ssl_key_usage=\"Digital Signature, Key Encipherment\"\n" " \n" " ssl_subject=\"CN=*.eu-west-1.webrootcloudav.com\" ssl_start_time=\"Tue Aug 22 00:00:00 2017 UTC\" ssl_end_time=\"Sat Sep 22 12:00:00 2018 UTC\" ssl_type=\"X.509 Certificate\" ssl_extended_key_usage=\"\" ssl_key_length=\"2048 bits\" ssl_key_usage=\"Digital Signature, Non-Repudiation, Key Encipherment\"\n" " \n" " ssl_subject=\"CN=*.us.static.hrsmart.com C=US S=Virginia O=Deltek, Inc. OU=Security Services\" ssl_start_time=\"Thu Jan 11 00:00:00 2018 UTC\" ssl_end_time=\"Sun Mar 31 12:00:00 2019 UTC\" ssl_type=\"X.509 Certificate\" ssl_extended_key_usage=\"Server Authentication, Client Authentication\" ssl_key_length=\"2048 bits\" ssl_key_usage=\"Digital Signature, Key Encipherment\"\n" " \n" " ssl_subject=\"CN=*.googleapis.com C=US S=California O=Google Inc\" ssl_start_time=\"Tue Mar 13 18:57:10 2018 UTC\" ssl_end_time=\"Tue Jun 5 18:17:00 2018 UTC\" ssl_type=\"X.509 Certificate\" ssl_extended_key_usage=\"Server Authentication, Client Authentication\" ssl_key_length=\"0 bits\" ssl_key_usage=\"Digital Signature, Certificate Signing, CRL Signing\"\n" " \n" " ssl_subject=\"CN=subscription.rhsm.redhat.com C=US S=North Carolina O=Red Hat, Inc. OU=Red Hat Network\" ssl_start_time=\"Thu May 18 16:30:24 2017 UTC\" ssl_end_time=\"Sat May 18 16:30:24 2019 UTC\" ssl_type=\"X.509 Certificate\" ssl_extended_key_usage=\"Server Authentication\" ssl_key_length=\"4096 bits\" ssl_key_usage=\"\"") 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