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"\b(access.log|osm_ms01.log|osm_ms01-diagnostic.log)\b", flags=re.MULTILINE) test_str = ("```\n" "-rw-r----- 1 osm_user osm_user 51200310 Dec 2 15:55 osm_ms01.log00025\n" "-rw-r----- 1 osm_user osm_user 51200201 Dec 2 19:52 osm_ms01.log00026\n" "-rw-r----- 1 osm_user osm_user 51200010 Dec 2 23:49 osm_ms01.log00027\n" "-rw-r----- 1 osm_user osm_user 1251657 Dec 3 02:53 osm_ms01.out00098\n" "-rw-r----- 1 osm_user osm_user 14534 Dec 3 03:23 osm_ms01.out00099\n" "-rw-r----- 1 osm_user osm_user 2124021 Dec 9 00:42 access.log\n" "-rw-r----- 1 osm_user osm_user 3406259 Dec 9 00:44 osm_ms01.out00100\n" "-rw-r----- 1 osm_user osm_user 14632 Dec 9 00:55 osm_ms01.out00101\n" "-rw-r----- 1 osm_user osm_user 4142712 Dec 9 01:00 osm_ms01-diagnostic.log\n" "-rw-r----- 1 osm_user osm_user 51200768 Dec 9 13:20 osm_ms01.log00028\n" "drwxr----- 2 osm_user osm_user 4096 Dec 11 00:58 metrics\n" "-rw-r----- 1 osm_user osm_user 1101990 Dec 11 01:38 osm_ms01.out\n" "-rw-r----- 1 osm_user osm_user 1150229 Dec 11 01:38 osm_ms01.log\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