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 single character of: a, b, c or d
    [[ab][cd]]
  • 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]
  • Character class intersection
    [\w&&[^\d]]
  • 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"([A-Z][a-z]+(\s[A-Z][a-z]+)*)" test_str = ("127.0.0.1 Amigo 30.08.2012 16:08:13 LOGIN OK\n" "192.168.100.2 Vasya Pupkin 30.08.2012 16:08:40 DONE_TASK 15 OK\n" "146.34.15.5 Eduard Petrovich Morozko 13.09.2013 5:04:50 DOWNLOAD_PLUGIN OK\n" "127.0.0.1 Eduard Petrovich Morozko 11.12.2013 10:11:12 WRITE_MESSAGE FAILED\n" "146.34.15.5 Eduard Petrovich Morozko 12.12.2013 21:56:30 WRITE_MESSAGE OK\n" "146.34.15.5 Eduard Petrovich Morozko 03.01.2014 03:45:23 LOGIN OK\n" "192.168.100.2 Vasya Pupkin 30.01.2014 12:56:22 SOLVE_TASK 18 ERROR\n" "127.0.0.1 Vasya Pupkin 14.11.2015 07:08:01 WRITE_MESSAGE OK\n" "192.168.100.2 Vasya Pupkin 19.03.2016 00:00:00 SOLVE_TASK 1 OK\n" "146.34.15.5 Eduard Petrovich Morozko 05.01.2021 20:22:55 DONE_TASK 48 FAILED\n" "127.0.0.1 Vasya Pupkin 14.10.2021 11:38:21 LOGIN OK\n" "12.12.12.12 Amigo 21.10.2021 19:45:25 SOLVE_TASK 18 OK\n" "120.120.120.122 Amigo 29.2.2028 5:4:7 SOLVE_TASK 18 OK") 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