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

r"
"
gmi

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"construit dans les ann[eé]es (\d{2,4})" test_str = ("[DATE DE CONSTRCUTION]\n\n" "R1 = date de constuction \\W (\\d{4}[-/]\\d{4}|((\\w{3,12})\\s)?\\d{4}|(\\d{1,2}(\\s?er)?)? \\w{3,10} \\d{4}|\\d{2}/\\d{2}/\\d{2,4}|[ST]\\d{1,4} \\d{4}|((fin|d[ée]but)\\s)?[1234](er|[eè]mes?) (semestre|trimestre)|courant \\w{3,10}(\\s\\d{4})?|\\w{3,10}/\\w{3,10} \\d{4}|((fin|d[ée]but)\\s)?(semestre|trimestre) \\d{1,4} \\d{4})\n\n" "date de constuction : 2000-2001\n" "date de constuction : 1999/2000\n" "date de constuction : 01/01/2020 \n" "date de constuction : 01/01/03 \n" "date de constuction : 1er janvier 2020\n" "date de constuction : 1 er janvier 2020\n" "date de constuction : 31 décembre 1997\n" "date de constuction : juin 2020\n" "date de constuction : Juillet/Juillet 2021\n" "date de constuction : courant Juin\n" "date de constuction : courant Juin 2003\n" "date de constuction : été 2021\n" "date de constuction : semestre 2 2028\n" "date de constuction : début semestre 2 2028\n" "date de constuction : S1 2024\n" "date de constuction : T3 2020\n" "date de constuction : 2ème semestre\n" "date de constuction : 1er semestre\n" "date de constuction : fin 2ème semestre\n" "date de constuction : début 2020\n" "date de constuction : fin 2022)\n\n" "[CONSTRUIT EN]\n\n" "R2 = construite?(\\s\\w{2,4})? (\\d{4}[-/]\\d{4}|((\\w{3,12})\\s)?\\d{4}|(\\d{1,2}(\\s?er)?)? \\w{3,10} \\d{4}|\\d{2}/\\d{2}/\\d{2,4}|[ST]\\d{1,4} \\d{4}|((fin|d[ée]but)\\s)?[1234](er|[eè]mes?) (semestre|trimestre)|courant \\w{3,10}(\\s\\d{4})?|\\w{3,10}/\\w{3,10} \\d{4}|((fin|d[ée]but)\\s)?(semestre|trimestre) \\d{1,4} \\d{4})\n\n" "construit en 1996\n" "construit en 2006\n" "construit en 2000-2001\n" "construit en 1999/2000\n" "construit le 01/01/2020 \n" "construit le 1er janvier 2020\n" "construit en Juin 2020 \n" "construit en Juillet/Juillet 2021\n" "construit courant Juin\n" "construit à l'été 2021\n" "construit au Semestre 2 2028, \n" "construit au S1 2024\n" "construit au T3 2020\n" "construit au 2ème semestre\n" "construit fin 2ème semestre\n" "construit début 2020\n" "construit fin 2022\n\n" "R3 = construit dans les ann[eé]es (\\d{2,4})\n" "construit dans les années 90 \n" "construit dans les années 2000\n\n" "construit au siècle dernier ??") matches = re.finditer(regex, test_str, re.MULTILINE | re.IGNORECASE) 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