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

/
/
gmi

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"{#include\s*([\w.]+)\s*}" test_str = ("{#include header.html}\n" " <header class=\"bg-gradient-to-r from-purple-700 to-indigo-800 shadow-lg w-full\">\n" " <div class=\"max-w mx-auto px-4 sm:px-6 lg:px-8 py-6\">\n" " <div class=\"flex flex-col items-center justify-between md:flex-row\">\n" " <a href=\"/\">\n" " <h1 class=\"mb-4 text-2xl font-bold text-white md:mb-0 md:text-3xl\">Header</h1>\n" " </a>\n" " <nav class=\"flex space-x-4\">\n" " <a href=\"/\">\n" " <a href=\"#\" class=\"text-white transition duration-150 ease-in-out hover:text-purple-200\">Home</a>\n" " </a>\n" " <a href=\"#\" class=\"text-white transition duration-150 ease-in-out hover:text-purple-200\">About</a>\n" " <a href=\"#\" class=\"text-white transition duration-150 ease-in-out hover:text-purple-200\">Contact</a>\n" " </nav>\n" " </div>\n" " </div>\n" " </header>\n\n" " <div class=\"flex flex-grow\">\n" " <aside class=\"w-72 bg-gray-100 scrollable-column\">\n" " <div class=\"p-6\">\n" " <h2 class=\"mb-4 text-xl font-semibold text-gray-800\">Directories</h2>\n" " {#each item in dirs}\n" " <div class=\"mb-3\">\n" " <a href=\"{item.link}\"\n" " class=\"font-medium text-indigo-600 transition duration-150 ease-in-out hover:text-indigo-800\">{item.name}</a>\n" " </div>\n" " {/each}\n" " </div>\n" " </aside>\n\n" " <main class=\"flex-grow bg-white scrollable-column\">\n" " <div class=\"p-6 md:p-8\">\n" " {#each item in files}\n" " <div class=\"space-y-4\">\n" " <div class=\"flex flex-col sm:flex-row border-b-2 border-gray-200 pb-4\">\n" " <div class=\"w-full sm:w-[150px] h-[150px] border-2 border-black flex items-center justify-center overflow-hidden mb-4 sm:mb-0 flex-shrink-0\">\n" " <a href=\"{item.link}\">\n" " <img src=\"{item.image}\" alt=\"thumbnail\" class=\"w-full h-full object-cover\">\n" " </a>\n" " </div>\n" " <div class=\"flex-grow pt-2 sm:pl-4\">\n" " <h3 class=\"mb-2 text-xl font-semibold\">\n" " <a href=\"{item.link}\"\n" " class=\"text-indigo-600 transition duration-150 ease-in-out hover:text-indigo-800\">{item.name}</a>\n" " </h3>\n" " <p class=\"text-black text-sm -mt-2 mb-2\">{item.date}</p>\n" " <p class=\"text-gray-600 text-lg\">{item.summery}</p>\n" " </div>\n" " </div>\n" " </div>\n" " {/each}\n" " </div>\n" " </main>\n" " </div>\n\n" " <footer class=\"bg-gray-800 text-white\">\n" " <div class=\"container mx-auto px-4 py-8\">\n" " <div class=\"flex flex-col items-center justify-between md:flex-row\">\n" " <div class=\"mb-4 text-2xl font-semibold md:mb-0\">Footer</div>\n" " <div class=\"flex space-x-4\">\n" " <a href=\"#\" class=\"transition duration-150 ease-in-out hover:text-purple-300\">Privacy</a>\n" " <a href=\"#\" class=\"transition duration-150 ease-in-out hover:text-purple-300\">Terms</a>\n" " <a href=\"#\" class=\"transition duration-150 ease-in-out hover:text-purple-300\">Contact</a>\n" " </div>\n" " </div>\n" " </div>\n" " </footer>\n" "{#include footer.html}\n") matches = re.finditer(regex, test_str, re.MULTILINE | re.IGNORECASE) 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