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"^(?:(52\-)|(1\-))?(\()?(?(1)[0-9]{2,3}|[2-9][0-9]{2})(?(3)\)\s?|(\-|[.]|\s|))(?(1)[0-9]|[2-9])[0-9]{2}(?(4)\4|(?:\-|[.]|\s)?)[0-9]{4}(\s?(?:x|ext|ext.|extension|Ext|Ext.|Extension|#)\s?[0-9]+)?$", flags=re.MULTILINE) test_str = ("Regular valid formats\n\n" "225-586-7777\n" "(223)249-4444\n" "(223) 234-3344\n" "223.456.2222\n" "2253451111\n" "223 334 4444\n\n" "1-325-586-7777\n" "1-(923)249-4444\n" "1-(923) 234-3344\n" "1-923.456.2222\n" "1-9253451111\n" "1-923 234 4444\n\n" "52-125-586-7777\n" "52-(123)249-4444\n" "52-(123) 234-3344\n" "52-123.456.2222\n" "52-1253451111\n" "52-123 134 4444\n\n" "Valid formats with extensions\n\n" "1-800-661-3696 x14700\n" "1-800-661-3696x14700\n" "1-800-661-3696 Extension 14700\n" "1-800-661-3696 ext14700\n\n" "325-586-7777 x123\n" "(323)249-4444x123\n" "(323) 234-3344 Ext 123\n" "323.456.2222 ext 124\n" "3253451111ext. 123\n" "323 334 4444extension234\n" "(223)456 7891 x 123\n" "(223)456 7891 ext 123\n" "(223)456 7891 ext. 123\n" "(223)456 7891 Ext 123\n" "(223)456 7891 Ext. 123\n" "(910)456-8970 x12\n" "(910)456-8970 #12\n" "(910)456-8970 extension12456\n" "(910)456-8970 Extension 12456\n\n" "Invalid formats\n\n" "444000-1111\n" "444-0001111\n" "444.000-1111\n" "444000 1111\n" "444 0001111\n" "444 000.1111\n" "444.0001111\n" "444000.1111\n" "444-000.1111\n" "(4440001111\n" "444)0001111\n" "440001111\n" "444000111111\n\n" "125-586-7777\n" "(123)249-4444\n" "(123) 234-3344\n" "123.456.2222\n" "1253451111\n" "123 134 4444\n\n" "125-586-7777\n" "(123)249-4444\n" "(123) 234-3344\n" "123.456.2222\n" "1253451111\n" "123 134 4444\n\n" "Invalid formats with extensions\n\n" "12-125-586-7777\n" "12-(123)249-4444\n" "12-(123) 234-3344\n" "12-123.456.2222\n" "12-1253451111\n" "12-123 134 4444\n\n" "12-444000-1111\n" "12-444-0001111\n" "12-444.000-1111\n" "12-444000 1111\n" "12-444 0001111\n" "12-444 000.1111\n" "12-444.0001111\n" "12-444000.1111\n" "12-444-000.1111\n" "12-(4440001111\n" "12-444)0001111\n" "12-440001111\n" "12-444000111111\n\n" "1-888-720-1275 x2 x2\n" "1-888-720-1275 2\n" "1-888-720-1275 x\n" "1-888-720-1275 Ext\n" "888-720-1275x\n\n" "1-444000-1111\n" "1-444-0001111\n" "1-444.000-1111\n" "1-444000 1111\n" "1-444 0001111\n" "1-444 000.1111\n" "1-444.0001111\n" "1-444000.1111\n" "1-444-000.1111\n" "1-(4440001111\n" "1-444)0001111\n" "1-440001111\n" "1-444000111111") 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