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"(?<=Rechnungsdatum)([\s]*)(\d{1,2}\.\d{1,2}\.\d{1,4}|\d{1,2}\.\d{1,2})" test_str = (" 1&1 Internet AG\n" " Elgendorfer Str. 57\n" " 56410 Montabaur\n\n" "Rechnung Rechnungsdatum 16.02.2012\n" " Rechnungsnummer 10000033321\n" " Vertragsnummer\n" " Kundennummer V4608229\n" " K6990000\n\n" "Musterfirma GmbH Bei Fragen: www.1und1.de/kontakt\n" "Herr Willi Mustermann Ihr Kundenbereich (mit Hilfe zur Anmeldung)\n" "Musterstraße 1 http://login.1und1.de\n" "12345 Musterhausen\n" " Aus Deutschland:\n" " Telefon: 0721 96 00\n" " (kostenfrei aus dem 1&1 Fest- und\n" " 1&1 Mobilfunknetz)\n\n" " Aus Österreich:\n" " Telefon: (+43) 1 311 92 22 (Kosten abhängig von\n" " Ihrem Festnetz-/Mobilfunkanbieter)\n\n" " Servicezeiten: täglich rund um die Uhr\n\n" "Ihre Rechnung (1&1 Website 5.0)\n\n" "Abrechnungszeitpunkt: 15.02.2012\n\n" "Pos. Die Leistungen im Überblick Tarif Einheiten Brutto (EUR) MwSt\n" "Basispreis\n\n" "1 Grundgebühr 4,99 EUR je Monat 6 Mon. 29,94 19%\n\n" "15.02.2012-15.08.2012 droegemueller-luebeck.de\n\n" "Zwischensumme (Netto) 25,16 EUR\n" "+ Mehrwertsteuer (19,00%) 4,78 EUR\n\n" "Zu zahlender Betrag 29,94 EUR\n\n" "Der Rechnungsbetrag wird wie vereinbart von Ihrem Konto Nr. 881XXXX, BLZ 23070700 abgebucht. Die letzten Ziffern der Kontonummer haben wir aus\n" "Sicherheitsgründen unkenntlich gemacht.\n\n" "Bei Fragen zu Ihrer Rechnung bieten wir Ihnen in Ihrem 1&1 Control-Center die Möglichkeit, eine E-Mail Anfrage an unsere Rechnungsabteilung zu richten.\n" "Das Kontaktformular finden Sie unter www.1und1.de/kontakt\n\n" "Vorstand: Henning Ahlert, Ralph Dommermuth, Matthias Ehrlich, Robert Hoffmann, Markus Huhn, Hans-Henning Kettler, Dr. Oliver Mauss, Jan Oetjen\n" "Aufsichtsratsvorsitzender: Michael Scheeren · HRB Montabaur 6484 · USt-IdNr.: DE811247114\n\n" "WestLB, BLZ 300 500 00, Konto 7904 865, IBAN DE61300500000007904865, SWIFT WELA DE DD\n") 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