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"^\s+(?P<user>[\w[:print:]]+) [\w\-\.]+ [[:print:]]+ ?\(v[\w\.]+\) \([\w\-\.]+\/\d+ \d+\)\, start \w+ \d+\/\d+ \d+\:\d+(\,\s(?P<licenses>\d+)\s\w+|)(\s+\(linger\:\s\d+\s\/\s\d+\))?$" test_str = ("\n" " userone host01 :78 APS Base (v19.100) (licserver/27010 7401), start Thu 5/14 15:31, 2 licenses\n" " userone host01 :78 APS Multi-core (Max. 16 cores) (v19.100) (licserver/27010 7501), start Thu 5/14 15:31, 4 licenses\n" " userone host01 :75 APS Base (v19.100) (licserver/27010 18901), start Thu 5/14 15:33, 2 licenses\n" " userone host01 :75 APS Multi-core (Max. 16 cores) (v19.100) (licserver/27010 19001), start Thu 5/14 15:33, 4 licenses\n" " userone host01 :76 APS Base (v19.100) (licserver/27010 18702), start Thu 5/14 15:34, 2 licenses\n" " userone host01 :76 APS Multi-core (Max. 16 cores) (v19.100) (licserver/27010 17002), start Thu 5/14 15:34, 4 licenses\n" " userone host01 :77 APS Base (v19.100) (licserver/27010 23302), start Thu 5/14 15:34, 2 licenses\n" " userone host01 :77 APS Multi-core (Max. 16 cores) (v19.100) (licserver/27010 23801), start Thu 5/14 15:34, 4 licenses\n" " userone host01 :60 APS Base (v19.100) (licserver/27010 23901), start Thu 5/14 15:34, 2 licenses\n" " userone host01 :60 APS Multi-core (Max. 16 cores) (v19.100) (licserver/27010 24001), start Thu 5/14 15:34, 4 licenses\n" " userone host01 :68 APS Base (v19.100) (licserver/27010 25501), start Thu 5/14 15:34, 2 licenses\n" " userone host01 :68 APS Multi-core (Max. 16 cores) (v19.100) (licserver/27010 25601), start Thu 5/14 15:34, 4 licenses\n" " userone host01 :58 APS Base (v19.100) (licserver/27010 22803), start Thu 5/14 15:34, 2 licenses\n" " userone host01 :58 APS Multi-core (Max. 16 cores) (v19.100) (licserver/27010 27801), start Thu 5/14 15:34, 4 licenses\n" " useronexr host01 :51 Spectre X Base (v19.100) (licserver/27010 61140), start Sat 5/16 13:41, 3 licenses\n" " useronexr host01 :52 Spectre X Base (v19.100) (licserver/27010 31125), start Sat 5/16 13:43, 3 licenses\n" " useronexr host01 :76 Spectre X Base (v19.100) (licserver/27010 53463), start Sat 5/16 13:47, 3 licenses\n" " useronexr host01 :69 Spectre X Base (v19.100) (licserver/27010 41523), start Sat 5/16 13:47, 3 licenses\n" " useronexr host01 :51 Spectre X Multi-core (Max. 16 cores) (v19.100) (licserver/27010 46233), start Sat 5/16 14:08, 6 licenses\n" " useronex host01 :52 Spectre X Multi-core (Max. 16 cores) (v19.100) (licserver/27010 32328), start Sat 5/16 14:10, 6 licenses\n" " useronex host01 :69 Spectre X Multi-core (Max. 16 cores) (v19.100) (licserver/27010 10953), start Sat 5/16 14:16, 6 licenses\n" " useronex host02 :76 Spectre X Multi-core (Max. 16 cores) (v19.100) (licserver/27010 32114), start Sat 5/16 14:17, 6 licenses\n" " useronexr host02 localhost:10 APS Base (v19.100) (licserver/27010 31935), start Sun 5/17 10:18, 2 licenses\n" " useronexr host02 localhost:10 APS Multi-core (Max. 16 cores) (v19.100) (licserver/27010 6614), start Sun 5/17 10:21, 4 licenses\n\n") 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