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
No Match

/
/
gmx

Test String

Code Generator

Language

Generated Code

# coding=utf8 # the above tag defines encoding for this document and is for Python 2.x compatibility import re regex = r""" \b \+?1? (?<separator>\s|-|\.)? (?: # area code with optional parentheses (?<area_code>[2-9][0-8]\d) |\((?&area_code)\) ) (?&separator)? (?: # exchange (?!555) [2-9] (?!11)\d\d ) (?&separator)? \d{4} # line \b """ test_str = ("212 718-1234\n" "(212)718-1234\n" "(212) 718-1234\n" "1(212)718-1234\n" "1-212-718-1234\n" "1.212.718.1234\n" "+1-212-718-1234\n" "+1.212.718.1234\n" "1-212-718-1234\n" "+1 (212) 718-1234\n\n" "# 1-VALID 2-VALID 4-VALID\n" "231 212 1234\n\n" "234-235-5678 is a valid telephone number with area code 234, central office prefix (exchange) 235, and line number 5678. \n\n" "12127181234\n" "(212)7181234\n\n\n" "# 1-INVALID 2-INVALID 4-INVALID\n" "091 012 1234\n" "# 1-INVALID 2-VALID 4-INVALID\n" "081 012 1234\n" "171 012 1234\n" "# 1-VALID 2-VALID 4-INVALID\n" "231 012 1234\n" "# 1-INVALID 2-INVALID 4-VALID\n" "091 212 1234\n" "# 1-INVALID 2-VALID 4-VALID\n" "081 212 1234\n" "171 212 1234\n" "231 555 1234\n\n" "867-5309 missing area code\n\n" "The number 234-911-5678 is invalid, because the central office code must not be in the form N11. 314-159-2653 is invalid, because the office code must not begin with 1. 123-234-5678 is invalid, because the NPA must not begin with 0 or 1.\n\n" "1 212) 718 1234\n\n" "121271812341212718123412127181234") matches = re.finditer(regex, test_str, re.MULTILINE | re.VERBOSE) for matchNum, match in enumerate(matches, start=1): print ("Match {matchNum} was found at {start}-{end}: {match}".format(matchNum = matchNum, start = match.start(), end = match.end(), match = match.group())) for groupNum in range(0, len(match.groups())): groupNum = groupNum + 1 print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = match.start(groupNum), end = match.end(groupNum), group = match.group(groupNum))) # Note: for Python 2.7 compatibility, use ur"" to prefix the regex and u"" to prefix the test string and substitution.

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