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

/
/
gm

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"^(?:(?!^\s|[ \-']{2}|[\d\r\n\t\f\v!\"#$%&()*+,\.\/:;<=>?@[\\\]^_`{|}~€‚ƒ„…†‡ˆ‰‹‘’“”•–—˜™›¡¢£¤¥¦§¨©ª«¬®¯°±²³´¶·¸¹º»¼½¾¿×÷№′″ⁿ⁺⁰‱₁₂₃₄]|\s$).){1,50}$" test_str = ("Regex matches: from 1 to 50 international letters separated by single delimiter ( -')\n" "Regex rejects: empty prefix/suffix, consecutive delimiters ( -'), digits, new line, tab, limited list of extended ASCII characters\n\n" "Jo Nesbø\n" "Pedro Almodóvar\n" "بيدرو ألمودوبار\n" "Sofija Jogailaitė\n" "Akira Kurosawa\n" "Куросава Акіра\n" "Куросава Акира\n" "黒澤明\n" "黑澤明\n" "আকিৰা কুৰোছাৱা\n" "Tyue' Tgshh\n" "CxCx5C5C\n" "AKIRA KUROSAWA\n" "Akir@ Kursawa\n" "Stev3 Smith\n" "STeve Smith\n" "Steve SMith\n" "Steve Sm1th\n" "Steve G. Smith\n" "d'Are to Beaware\n" "Hyoung Kyoung Wu\n" "Mike O'Neal\n" "Steve Johnson-Smith\n" "Jozef-Schmozev Hiemdel\n" "O Henry Smith\n" "Mathais d'Arras\n" "Martin Luther King Jr\n" "Downtown-James Brown\n" "Darren McCarty\n" "An Ni\n" "O. Henry McCarty\n" "George De FunkMaster\n" "Kurtis B-Ball\n" "Ahmad el Jeffe\n" "John Smith\n" "'John Smith") matches = re.finditer(regex, test_str, re.MULTILINE) 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