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"(?:[a-z0-9+!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|\"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*\")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])", flags=re.IGNORECASE) test_str = ("[a-zA-Z0-9-_.+]+@[a-zA-Z0-9-_.]+\n\n" "ekoprasetyo.crb@outlook.com\n" "db.maulana@gmail.com.\n" " dee.wien@yahoo.com. .\n" "\"deninainggolan@yahoo.co.id\" \n" "Fajar.rohita@hotmail.com klaas knot (firmansya1404@gmail.aero); \n" "dydmm, sss <fransisca+jw@gmail.com>, donny_tri_wardono@yahoo.co.id thank a\n" "\"Helpdesk | Energiem**ine\" <helpdesk@ene---ine.nl>\n" "invalid: John..Doe@example.com \n" "valid: John.Doe@example.com\n\n" "Valid addresses from https://en.wikipedia.org/wiki/Email_address\n" "simple@example.com\n" "very.common@example.com\n" "FirstName.LastName@EasierReading.org\n" "x@example.com\n" "long.email-address-with-hyphens@and.subdomains.example.com\n" "user.name+tag+sorting@example.com\n" "name/surname@example.com\n" "admin@example\n" "example@s.example\n" "\" \"@example.org\n" "\"john..doe\"@example.org\n" "mailhost!username@example.org\n" "\"very.(),:;<>[]\\\".VERY.\\\"very@\\\\ \\\"very\\\".unusual\"@strange.example.com\n" "user%example.com@example.org\n" "user-@example.org\n" "postmaster@[123.123.123.123]\n" "postmaster@[IPv6:2001:0db8:85a3:0000:0000:8a2e:0370:7334]\n" "_test@[IPv6:2001:0db8:85a3:0000:0000:8a2e:0370:7334]") 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