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""" (?(DEFINE) (?<quote>['"]) (?<pair> (?> \w+ |(?: (?<pairQuote>(?&quote))[^'"]+?\k<pairQuote> ) ) \s*\: ) (?<string> (?<stringQuote>(?&quote))[\S\s]*?(?<!\\)\k<stringQuote> ) (?<integer>\-?\d+(?:\.\d+)?(?:e[-+]\d+)?) (?<scalar>true|false|null|(?&integer)) (?<elements> \s*(?&value) (?(R&array)|(?>(?:\s*\,(?&elements))|\s*)) ) (?<array>\[(?>(?&elements)|\s*)\]) (?<value> (?&object) |(?&string) |(?&scalar) |(?&array) ) (?<members> \s*(?&pair)\s*(?&value) (?(R&object)|(?>(?:\s*\,(?&members))|\s*)) ) (?<object>\{(?&members)?\}) ) \A(?&object)\Z """, flags=re.IGNORECASE | re.MULTILINE | re.VERBOSE) test_str = ("{\"menu\": {\n" " \"header\": \"SVG Viewer\",\n" " \"items\": [\n" " {\"id\": \"Open\"},\n" " {\"id\": \"OpenNew\", \"label\": \"Open New\"},\n" " null,\n" " {\"id\": \"ZoomIn\", \"label\": \"Zoom In\"},\n" " {\"id\": \"ZoomOut\", \"label\": \"Zoom Out\"},\n" " {\"id\": \"OriginalView\", \"label\": \"Original View\"},\n" " null,\n" " {\"id\": \"Quality\"},\n" " {\"id\": \"Pause\"},\n" " {\"id\": \"Mute\"},\n" " null,\n" " {\"id\": \"Find\", \"label\": \"Find...\"},\n" " {\"id\": \"FindAgain\", \"label\": \"Find Again\"},\n" " {\"id\": \"Copy\"},\n" " {\"id\": \"CopyAgain\", \"label\": \"Copy Again\"},\n" " {\"id\": \"CopySVG\", \"label\": \"Copy SVG\"},\n" " {\"id\": \"ViewSVG\", \"label\": \"View SVG\"},\n" " {\"id\": \"ViewSource\", \"label\": \"View Source\"},\n" " {\"id\": \"SaveAs\", \"label\": \"Save As\"},\n" " null,\n" " {\"id\": \"Help\"},\n" " {\"id\": \"About\", \"label\": \"About Adobe CVG Viewer...\"}\n" " ],\n" " \"test\": [\n" " \"Some value\",\n" " 4,\n" " null,{}\n" " ],\n" " \"empty_array\":[-0.34E+4]\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