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"^(?:(?:ds|crl|ocsp|dnl\-[0,1][0-9]\.geo|(?:[sp][0,1][0-9]|downloads)\.upd)\.kaspersky|downloads[0-9]?\.kaspersky\-labs)\.com$", flags=re.MULTILINE | re.IGNORECASE) test_str = ("ds.kaspersky.com\n" "dnl-01.geo.kaspersky.com\n" "dnl-02.geo.kaspersky.com\n" "dnl-03.geo.kaspersky.com\n" "dnl-04.geo.kaspersky.com\n" "dnl-05.geo.kaspersky.com\n" "dnl-06.geo.kaspersky.com\n" "dnl-07.geo.kaspersky.com\n" "dnl-08.geo.kaspersky.com\n" "dnl-09.geo.kaspersky.com\n" "dnl-10.geo.kaspersky.com\n" "dnl-11.geo.kaspersky.com\n" "dnl-12.geo.kaspersky.com\n" "dnl-13.geo.kaspersky.com\n" "dnl-14.geo.kaspersky.com\n" "dnl-15.geo.kaspersky.com\n" "dnl-16.geo.kaspersky.com\n" "dnl-17.geo.kaspersky.com\n" "dnl-18.geo.kaspersky.com\n" "dnl-19.geo.kaspersky.com\n" "dnl-00.geo.kaspersky.com\n" "s00.upd.kaspersky.com\n" "s01.upd.kaspersky.com\n" "s02.upd.kaspersky.com\n" "s03.upd.kaspersky.com\n" "s04.upd.kaspersky.com\n" "s05.upd.kaspersky.com\n" "s06.upd.kaspersky.com\n" "s07.upd.kaspersky.com\n" "s08.upd.kaspersky.com\n" "s09.upd.kaspersky.com\n" "s10.upd.kaspersky.com\n" "s11.upd.kaspersky.com\n" "s12.upd.kaspersky.com\n" "s13.upd.kaspersky.com\n" "s14.upd.kaspersky.com\n" "s15.upd.kaspersky.com\n" "s16.upd.kaspersky.com\n" "s17.upd.kaspersky.com\n" "s18.upd.kaspersky.com\n" "s19.upd.kaspersky.com\n" "p00.upd.kaspersky.com\n" "p01.upd.kaspersky.com\n" "p02.upd.kaspersky.com\n" "p03.upd.kaspersky.com\n" "p04.upd.kaspersky.com\n" "p05.upd.kaspersky.com\n" "p06.upd.kaspersky.com\n" "p07.upd.kaspersky.com\n" "p08.upd.kaspersky.com\n" "p09.upd.kaspersky.com\n" "p10.upd.kaspersky.com\n" "p11.upd.kaspersky.com\n" "p12.upd.kaspersky.com\n" "p13.upd.kaspersky.com\n" "p14.upd.kaspersky.com\n" "p15.upd.kaspersky.com\n" "p16.upd.kaspersky.com\n" "p17.upd.kaspersky.com\n" "p18.upd.kaspersky.com\n" "p19.upd.kaspersky.com\n" "downloads.upd.kaspersky.com\n" "crl.kaspersky.com\n" "ocsp.kaspersky.com\n" "downloads.kaspersky-labs.com\n" "downloads0.kaspersky-labs.com\n" "downloads1.kaspersky-labs.com\n" "downloads2.kaspersky-labs.com\n" "downloads3.kaspersky-labs.com\n" "downloads4.kaspersky-labs.com\n" "downloads5.kaspersky-labs.com\n" "downloads6.kaspersky-labs.com\n" "downloads7.kaspersky-labs.com\n" "downloads8.kaspersky-labs.com\n" "downloads9.kaspersky-labs.com\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