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""" ^ #whitespace ([ ]*) (?: # Error position - line location (-{6,})([\^]) | # Line number ([\d]+) # Line number delim ([\|]) # Code indent ([ \t]*) (?: # Comment ? ([\/]{2}.+)? | # Else code block line (.*) ) $ ) | # Function delim token (at +) # Function (.+?) # (, Path base ([\(].+?) # File ([^\/]+?) # Line:char (?:(:)(\d+))? (?:(:)(\d+))? # Function path ([\)]) """, flags=re.MULTILINE | re.VERBOSE) test_str = (" watching /Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/functions/index.styl\n" "ParseError: inject/code-custom.styl:125:44\n" " 121| else\n" " 122| // Add room for window controls\n" " 123| body.mac \n" " 124| // Only target first tab bar\n" " 125| [data-keybinding-context=\"1\"] .tabs-and-actions-container\n" "---------------------------------------------------^\n" " 126| & .tabs-and-actions-container\n" " 127| padding-left: 9em\n" " 128| & .dragging-area-left-padding\n\n" "expected \":\", got \")\"\n\n" " at Parser.error (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:259:11)\n" " at Parser.expect (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:287:12)\n" " at Parser.ternary (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:1964:12)\n" " at Parser.negation (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:1953:17)\n" " at Parser.expression (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:1932:24)\n" " at Parser.ternary (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:1963:27)\n" " at Parser.negation (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:1953:17)\n" " at Parser.expression (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:1932:24)\n" " at Parser.primary (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:2250:23)\n" " at Parser.member (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:2174:21)\n" " compiled inject/FontLoad.css\n" " watching inject/FontLoad.styl\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