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

/
/

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"[]\r\n]+\d{4}\/\d{2}\/\d{2}\s\d{2}\:\d{2}\:\d{2}\.\d{7}\s\d{4}" test_str = ("2015/08/13 18:20:35.0450892 1104 10780 Shared * START * Service startup\n" "2015/08/13 18:20:35.0536222 1104 10780 Agent WU client version 10.0.10240.16397\n" "2015/08/13 18:20:35.0538960 1104 10780 Agent SleepStudyTracker: Machine is non-AOAC. Sleep study tracker disabled.\n" "2015/08/13 18:20:35.0539537 1104 10780 Agent Base directory: C:\\WINDOWS\\SoftwareDistribution\n" "2015/08/13 18:20:35.0540354 1104 10780 Shared UpdateNetworkState Ipv6, cNetworkInterfaces = 8.\n" "2015/08/13 18:20:35.0540549 1104 10780 Shared UpdateNetworkState Ipv4, cNetworkInterfaces = 2.\n" "2015/08/13 18:20:35.0544494 1104 10780 Shared Network state: Connected\n" "2015/08/13 18:20:35.0580648 1104 10780 Shared UpdateNetworkState Ipv6, cNetworkInterfaces = 8.\n" "2015/08/13 18:20:35.0580736 1104 10780 Shared UpdateNetworkState Ipv4, cNetworkInterfaces = 2.\n" "2015/08/13 18:20:35.0580804 1104 10780 Shared Power status changed\n" "2015/08/13 18:20:35.0718558 1104 10780 Agent Initializing global settings cache\n" "2015/08/13 18:20:35.0718573 1104 10780 Agent WSUS server: NULL\n" "2015/08/13 18:20:35.0718583 1104 10780 Agent WSUS status server: NULL\n" "2015/08/13 18:20:35.0718593 1104 10780 Agent Target group: (Unassigned Computers)\n" "2015/08/13 18:20:35.0718602 1104 10780 Agent Windows Update access disabled: No\n" "2015/08/13 18:20:35.0723643 1104 10780 Agent Timer: 855E8A7C-ECB4-4CA3-B045-1DFA50104289, Expires 2015-08-13 22:22:28, not idle-only, <NULL>network-only\n" "2015/08/13 18:20:35.0723702 1104 10780 Agent Timer: 29A863E7-8609-4D1E-B7CD-5668F857F1DB, Expires 2015-08-14 17:45:53, not idle-only, not network-only\n" "2015/08/13 18:20:35.0767535 1104 10780 Agent Initializing Windows Update Agent\n" "2015/08/13 18:20:35.0768073 1104 10780 DownloadManager Download manager restoring 0 downloads\n" "2015/08/13 18:20:35.0768674 1104 10780 Agent CPersistentTimeoutScheduler | GetTimer, returned hr = 0x00000000\n" "2015/08/13 18:20:35.2159607 1104 11340 DownloadManager PurgeExpiredFiles::Found 0 expired files to delete.\n" "2015/08/13 18:20:35.2217267 1104 11340 DownloadManager PurgeExpiredUpdates::Found 606 non expired updates.\n" "2015/08/13 18:20:35.3462873 1104 11340 DownloadManager PurgeExpiredUpdates::Found 0 expired updates.\n" "2015/08/13 18:20:35.3466012 1104 11340 Shared Effective power state: AC") matches = re.search(regex, test_str) if matches: print ("Match was found at {start}-{end}: {match}".format(start = matches.start(), end = matches.end(), match = matches.group())) for groupNum in range(0, len(matches.groups())): groupNum = groupNum + 1 print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = matches.start(groupNum), end = matches.end(groupNum), group = matches.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