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

/
/
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"\(PERMBLOCK\)\s(?<IP>[.0-9]*)\s\((?<country>.{2}).*? - (?<date>.*)" test_str = ("180.76.15.158 # lfd: (PERMBLOCK) 180.76.15.158 (CN/China/baiduspider-180-76-15-158.crawl.baidu.com) has had more than 4 temp blocks in the last 86400 secs - Mon Jun 11 05:20:35 2018\n" "80.211.140.69 # lfd: (PERMBLOCK) 80.211.140.69 (IT/Italy/host69-140-211-80.serverdedicati.aruba.it) has had more than 4 temp blocks in the last 86400 secs - Mon Jun 11 05:39:16 2018\n" "94.65.235.31 # lfd: (PERMBLOCK) 94.65.235.31 (GR/Greece/ppp-94-65-235-31.home.otenet.gr) has had more than 4 temp blocks in the last 86400 secs - Mon Jun 11 18:40:52 2018\n" "94.71.194.156 # lfd: (PERMBLOCK) 94.71.194.156 (GR/Greece/athedsl-4511380.home.otenet.gr) has had more than 4 temp blocks in the last 86400 secs - Tue Jun 12 02:24:44 2018\n" "114.207.112.188 # lfd: (PERMBLOCK) 114.207.112.188 (KR/Republic of Korea/114-207-112-188.tongkni.co.kr) has had more than 4 temp blocks in the last 86400 secs - Tue Jun 12 12:12:10 2018\n" "94.64.71.183 # lfd: (PERMBLOCK) 94.64.71.183 (GR/Greece/ppp-94-64-71-183.home.otenet.gr) has had more than 4 temp blocks in the last 86400 secs - Wed Jun 13 03:54:37 2018\n" "89.210.18.91 # lfd: (PERMBLOCK) 89.210.18.91 (GR/Greece/ppp089210018091.access.hol.gr) has had more than 4 temp blocks in the last 86400 secs - Wed Jun 13 04:07:48 2018\n" "94.65.149.72 # lfd: (PERMBLOCK) 94.65.149.72 (GR/Greece/ppp-94-65-149-72.home.otenet.gr) has had more than 4 temp blocks in the last 86400 secs - Fri Jun 15 05:22:46 2018\n" "94.64.70.87 # lfd: (PERMBLOCK) 94.64.70.87 (GR/Greece/ppp-94-64-70-87.home.otenet.gr) has had more than 4 temp blocks in the last 86400 secs - Sun Jun 17 07:06:11 2018\n" "94.64.66.189 # lfd: (PERMBLOCK) 94.64.66.189 (GR/Greece/ppp-94-64-66-189.home.otenet.gr) has had more than 4 temp blocks in the last 86400 secs - Mon Jun 18 00:28:35 2018\n" "180.76.15.6 # lfd: (PERMBLOCK) 180.76.15.6 (CN/China/baiduspider-180-76-15-6.crawl.baidu.com) has had more than 4 temp blocks in the last 86400 secs - Tue Jun 19 22:15:29 2018\n" "94.65.145.144 # lfd: (PERMBLOCK) 94.65.145.144 (GR/Greece/ppp-94-65-145-144.home.otenet.gr) has had more than 4 temp blocks in the last 86400 secs - Wed Jun 20 01:13:08 2018\n" "180.76.15.145 # lfd: (PERMBLOCK) 180.76.15.145 (CN/China/baiduspider-180-76-15-145.crawl.baidu.com) has had more than 4 temp blocks in the last 86400 secs - Thu Jun 21 13:55:36 2018\n" "2.84.214.95 # lfd: (PERMBLOCK) 2.84.214.95 (GR/Greece/ppp-2-84-214-95.home.otenet.gr) has had more than 4 temp blocks in the last 86400 secs - Thu Jun 21 20:39:07 2018") 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