Regular Expressions 101

Save & Manage Regex

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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"data-title=\"(.*?)\"") test_str = "<div class=\"url-block\"><a href=\"https://developers.google.com/speed/docs/insights/OptimizeImages\" target=\"_blank\">Optimize the following images</a> to reduce their size by 231.2KiB (55% reduction).<ul><li>Compressing and resizing <span class=\"url-external\" data-title=\"http://gotrangtri.vicoders.com/wp-content/uploads/2016/05/ban-tra-go-cong-nghiep-hien-dai-ghs-4188-1-1b-350x350.jpg\">http://gotrangtri.vicoders.com/…ghiep-hien-dai-ghs-4188-1-1b-350x350.jpg</span> could save 36.3KiB (85% reduction).</li><li>Compressing and resizing <span class=\"url-external\" data-title=\"http://gotrangtri.vicoders.com/wp-content/uploads/2016/05/ban-tra-go-cong-nghiep-phong-khach-ghs-4193-23-350x350.jpg\">http://gotrangtri.vicoders.com/…hiep-phong-khach-ghs-4193-23-350x350.jpg</span> could save 34.3KiB (85% reduction).</li><li>Compressing and resizing <span class=\"url-external\" data-title=\"http://gotrangtri.vicoders.com/wp-content/uploads/2016/04/ban-tra-go-cong-nghiep-hien-dai-ghs-4155-23-350x350.jpg\">http://gotrangtri.vicoders.com/…-nghiep-hien-dai-ghs-4155-23-350x350.jpg</span> could save 31.5KiB (86% reduction).</li><li>Compressing and resizing <span class=\"url-external\" data-title=\"http://gotrangtri.vicoders.com/wp-content/uploads/2016/05/ban-tra-phong-khach-go-cong-nghiep-ghs-4185-13-350x350.jpg\">http://gotrangtri.vicoders.com/…h-go-cong-nghiep-ghs-4185-13-350x350.jpg</span> could save 27KiB (86% reduction).</li><li>Compressing and resizing <span class=\"url-external\" data-title=\"http://gotrangtri.vicoders.com/wp-content/uploads/2016/05/ke-tivi-go-cong-nghiep-hien-dai-ghs-3194-13-350x350.jpg\">http://gotrangtri.vicoders.com/…-nghiep-hien-dai-ghs-3194-13-350x350.jpg</span> could save 24.4KiB (83% reduction).</li><li>Compressing and resizing <span class=\"url-external\" data-title=\"http://gotrangtri.vicoders.com/wp-content/uploads/2016/07/banner-xa-kho-noi-that-7.gif\">http://gotrangtri.vicoders.com/…ads/2016/07/banner-xa-kho-noi-that-7.gif</span> could save 22.2KiB (40% reduction).</li><li>Compressing and resizing <span class=\"url-external\" data-title=\"http://gotrangtri.vicoders.com/wp-content/uploads/2016/04/ke-tivi-phong-khach-kieu-dang-hien-dai-ghs-363-7b-350x350.jpg\">http://gotrangtri.vicoders.com/…ieu-dang-hien-dai-ghs-363-7b-350x350.jpg</span> could save 21.1KiB (85% reduction).</li><li>Compressing and resizing <span class=\"url-external\" data-title=\"http://gotrangtri.vicoders.com/wp-content/uploads/2016/06/tu-de-giay-nho-phong-cach-hien-dai-ghs-5129-13b-350x350.jpg\">http://gotrangtri.vicoders.com/…g-cach-hien-dai-ghs-5129-13b-350x350.jpg</span> could save 18.5KiB (83% reduction).</li><li>Losslessly compressing <span class=\"url-external\" data-title=\"http://gotrangtri.vicoders.com/wp-content/uploads/2016/07/banner-gio-vang-go-home2.gif\">http://gotrangtri.vicoders.com/…ads/2016/07/banner-gio-vang-go-home2.gif</span> could save 8.9KiB (14% reduction).</li><li>Losslessly compressing <span class=\"url-external\" data-title=\"http://gotrangtri.vn/wp-content/uploads/2016/01/banner-icon-ngo-nghinh-san-.gif\">http://gotrangtri.vn/…/2016/01/banner-icon-ngo-nghinh-san-.gif</span> could save 7.1KiB (11% reduction).</li></ul></div>" 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