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"^(?P<KEY>[^=#\s]+)=(?P<VALUE>.*)$", flags=re.MULTILINE) test_str = ("app=tcp/444\n" "# Catchs only Key:app Value:tcp > should catch Key:app Value:tcp/444 \n\n" "catdt=Network-based \n" "# Current result: \n" "# catdt:'Network'\n" "# \n" "# Shoud be:\n" "# catdt:'Network-based' \n\n" "eventId=123123 externalId=11111\n" "# Current result:\n" "# eventId:'123123 externalId=11111'\n" "#\n" "# Should catch\n" "# eventId: '123123'\n" "# externalId: '111111'\n\n" "src=2.3.4.5\n" "# Current result:\n" "# src:'2'\n" "#\n" "# Should catch\n" "# src: '2.3.4.5'\n\n" "eventAnnotationEndTime=1493293598\\=aaa00\n" "# Should be:\n" "# eventAnnotationEndTime: '1493293598\\=aaa00'\n\n" "eventAnnotationEndTimeA=1493293598A\\=aaa01 \n" "eventAnnotationEndTimeB=1493293598\\=aaa02\n" "# Should be:\n" "# eventAnnotationEndTimeA: '1493293598\\=aaa01'\n" "# eventAnnotationEndTimeB: '1493293598\\=aaa02'\n\n\n" "sourceTranslatedZoneURI=/All Zones/ArcSight System/Private Address Space Zones/RFC1918: 172.3.0.0-172.3.255.255\n" "# Should be:\n" "# ourceTranslatedZoneURI: '/All Zones/ArcSight System'") 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