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"(<script\b[^><]*>)(.*?)(<\/script>)|\bon\w+\s*=\s*\K(?|(\")([^\"]+)\"|(')([^']+)')", flags=re.IGNORECASE | re.DOTALL) test_str = ("<div id='content' onClick='abc()'>Lorem On='abc' ipsum on to</div>\n" "<input id='a' type='range'>\n" "<input id='b' type='range'>\n" "<script>abc();</script>\n\n\n\n" "Jan23: The following is an addition set of tests including escaping quotes and .replace(/'/ situations that can cause problems.\n\n\n" " <div id='content'\n" " onClick='yyy(\"ere\\'xyz\\'\").value=\\'ewew\\'; yyy(\"jhrhej\")'\n" " >Lorem On='abc' ipsum on to</div>\n\n\n" " <input id='a' type='range'\n" " onPress=\"xxx(document.getElementById(\\\"abc\\\"))\"\n" " onSomething=\"yyy(\\'fehrje\\')\"\n" " onSomethingElse=\"document.getElementById('content').innerHTML.replace(/\"/g, \\\"dq\\\")\">\n" " <input id='b' type='range'>\n\n" " <script>\n" " function abc() {console.log('abc()');};\n" " function xxx(elem) {console.log('xxx:'+elem.className);};\n" " function yyy(str) {console.log('yyy:'+str);};\n\n" " yyy(\"ere\\'xyz\\'\");\n" " yyy(\"jhrhej\");\n\n" " var aaa=document.getElementById('content').innerHTML;\n" " var bbb=document.getElementById('content').innerHTML;\n" " abc();\n" " aaa.replace(/'/g, \"single-quotes\");\n" " bbb.replace(/'/g, 'single-quotes');\n" " aaa.replace(/\"/g, \"quotes\");\n" " bbb.replace(/\"/g, 'quotes');\n" " </script>\n\n" "</body>\n" "</html>") 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