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]
  • Character class intersection
    [\w&&[^\d]]
  • 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"^[ \t]*\*[A-Z]{2,3},\s*(?:[ART]|RSS?)\.?[\n\r](?:(?!^[ \t]*\*[A-Z]{2,3},\s*(?:[ART]|RSS?)\.?[\n\r])[\s\S])+", flags=re.MULTILINE) test_str = ("*GW, A\n" "This is my very first line. The asterics defines a new block, followed by the initials (2-3 chars), a comma, a (possible) space and a code that could be A, R, T, RS or RSS. Followed by that is an optional dot. Linebreak afterwards, where the text comes.\n\n" " *JP, R.\n" " New block here, as the line (kind of) starts with an asterics. Indentations with 4 spaces or a tab means that it is a second level thing only, that does not need to be stripped away necessarily.\n\n" " But as you can see, a block can be devided into several\n" " lines, \n\n" " even with multiple lines.\n\n" " *GML, T.\n" " And so we continue...\n\n" " Let's just make sure that a line can start with an\n" " *asterics, without breaking the whole thing.\n" " *GW, RS\n" " Yet another block here.\n\n" " *GW, RSS.\n" " And a very final one.\n\n" " Spread over several lines.\n\n" "*TA, RS.\n" "First level all of a sudden again.\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