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"-(?!(?:Jan|Feb|Mar|Apr|May|Ju[nl]|Aug|Sep|Oct|Nov|Dec)$).*", flags=re.MULTILINE) test_str = (" ID GB_ACC Symbol\n" "1 ILMN_1655796 XM_001127871.1 3-Mar\n" "2 ILMN_1656409 NM_172311.1 STON1-GTF2A1L\n" "3 ILMN_1659893 NM_017418.1 1-Dec\n" "4 ILMN_1662905 NM_001018136.1 NME1-NME2\n" "5 ILMN_1669592 NM_001005416.1 12-Mar\n" "6 ILMN_1670188 NM_172089.2 TNFSF12-TNFSF13\n" "7 ILMN_1677318 NM_001002266.1 8-Mar\n" "8 ILMN_1677446 NM_199203.1 TMEM189-UBE2V1\n" "9 ILMN_1681101 NM_017923.2 10-Sep\n" "10 ILMN_1683974 NM_001003819.1 TRIM6-TRIM34\n" "11 ILMN_1693430 NM_001018136.1 NME1-NME2") 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