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"((?<=\()\S+(?=%\))|^\S+(?=\s\[))", flags=re.MULTILINE) test_str = ("0\n" "1991 (38.26%)\n" "1018 (41.52%)\n" "438 (35.12%)\n" "771 (35.16%)\n" "244 (35.72%)\n" "343 (32.48%)\n" "316 (40.51%)\n" "177 (33.84%)\n" "133 (41.18%)\n" "792 (35.92%)\n" "3190 (61.30%)\n" "1426 (58.16%)\n" "803 (64.39%)\n" "1415 (64.52%)\n" "436 (63.84%)\n" "711 (67.33%)\n" "463 (59.36%)\n" "345 (65.97%)\n" "187 (57.89%)\n" "1403 (63.63%)\n" "44.00 [38.00 - 50.00]\n" "43.00 [37.00 - 49.00]\n" "43.00 [37.00 - 49.00]\n" "44.00 [38.00 - 50.00]\n" "44.00 [39.00 - 50.00]\n" "44.00 [38.00 - 50.00]\n" "43.00 [37.00 - 49.00]\n" "45.00 [39.00 - 51.00]\n" "44.00 [37.00 - 50.00]\n" "45.00 [38.00 - 51.00]\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