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

/
/
gm

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"[^[:print:]]\[[^a-zA-Z]*[a-zA-Z]" test_str = ("[BEGIN TYPESCRIPT]\n" "Linux dcim-mao 4.19.0-20-cloud-amd64 #1 SMP Debian 4.19.235-1 (2022-03-17) x86_64\n\n" "The programs included with the Debian GNU/Linux system are free software;\n" "the exact distribution terms for each program are described in the\n" "individual files in /usr/share/doc/*/copyright.\n\n" "Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent\n" "permitted by applicable law.\n" "Last login: Mon Jul 10 08:00:55 2023 from 172.17.0.2\n\n" "[?2004hroot@dcim-mao:~# cd\n" "[?2004l\n" "[?2004hroot@dcim-mao:~# ls\n" "[?2004l\n" "[?2004hroot@dcim-mao:~# cd /\n" "[?2004l\n" "[?2004hroot@dcim-mao:/# ls\n" "[?2004l\n" "app etc media public srv usr\n" "bin home mnt root supervisor.conf var\n" "boot lib opt run sys\n" "dev lib64 proc sbin tmp\n" "[?2004hroot@dcim-mao:/# \n" "[END TYPESCRIPT]") matches = re.finditer(regex, test_str, re.MULTILINE) 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