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
Processing...

Test String

Code Generator

Language

Generated Code

import re regex = re.compile(r"(?:(?<=^)|(?<=\s))((?:2[0-5][0-5]|1[0-9][0-9]|[1-9][0-9]|[0-9])(?:\.(?:2[0-5][0-5]|1[0-9][0-9]|[1-9][0-9]|[0-9])){3})(?=\s|$)") test_str = ("IP Address:\n" "93.114.205.169\n" "0.0.0.0\n" "0.0.0.0\n" "10.10.10.10\n" "99.99.99.99\n" "199.199.199.199\n" "255.255.255.255\n" "256.256.256.256\n" "02.02.02.02\n" "111.222.13.255\n" "1.2.3.4\n" "1.2.3.4.5\n" "11.22.33.44\n" "11.22.33.44.55\n" "255.0.1.254\n" "255.0.1.254\n" "In a text 255.0.1.254 there is an IP address\n" "In a text 10.10.10.10 there is an IP address\n" "In a text 93.114.205.169 there is an IP address\n\n" "Domain:\n" "example.com\n" "https://sub5-7.example.com/\n" "https://sub5-7.example.com\n" "sub.sub2.example.com\n" "www.example.com\n" "https://sub.example.com\n" "http://example.com\n" "ftp://sub.mit-example222.com\n" "In a text www.example.com there is an domain.\n" "In a text https://sub5-7.example.com there is an domain.\n" "In a text www.example.com there is an domain.\n\n" "URL\n" "93.114.205.169/path\n" "example.com/path\n" "sub.example.com/path\n" "93.114.205.169/path\n" "https://sub5-7.example.com/\n" "http://example.com/\n" "example.com/\n" "sub.example.com/\n" "www.--example.com/\n" "www.examp--le.com/\n" "www.example.co/\n" "www.example.c/\n" "example.com/path\n" "sub.example.com/path\n" "sub.example.com/path\n" "sub.example.com/path\n" "sub.example.com/path/path/path/p/a/q/1$%h\n" "sub.example.com/path/path/path/p/a/q/1$%1fh\n" "sub.example.com/path/path/%aa%1f%3dpath/p/a/q/1$%1fh\n" "https://sub.example.com/path/path\n" "http://sub.example.com/path/path\n" "http://something.com/#$SLJFHsdq32908432098=!~abc\n" "In a text example.com/path there is an URL path.\n" "In a text www.example.com/path there is an URL path.\n" "In a text www.blog.example.com/path there is an URL path.\n" "In a text sub.example.com/paththere is an URL path.\n" "In a text sub.example.com/path/path/path/p/a/q/1$%h there is an URL path.\n" "In a text sub.example.com/path/path/path/p/a/q/ there is an URL path.\n") matches = regex.finditer(test_str) for match_num, match in enumerate(matches, start=1): print(f"Match {match_num} was found at {match.start()}-{match.end()}: {match.group()}") for group_num, group in enumerate(match.groups(), start=1): print(f"Group {group_num} found at {match.start(group_num)}-{match.end(group_num)}: {group}")

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