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"
"
gms

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"(^\d+(?!\.).*?)(?=^\s*\d)" test_str = ("7. On 6 March 2013, the Appeals Chamber filed the Decision on Victim \n" "Participation, in which it decided that the victims “may, through their legal \n\n" "1\n" " The full citation, including the ICC registration reference of all designations and abbreviations used in \n" "this judgment are included in Annex 1. \n" "2\n" " A more detailed procedural history is set out in Annex 2 of this judgment. \n" "ICC-01/04-02/12-271-Corr 07-04-2015 7/117 EK A\n\n" " 8/117 \n" "representatives, participate in the present appeal proceedings for the purpose of \n" "presenting their views and concerns in respect of their personal interests in the issues \n" "on appeal”.3\n\n" "8. On 19 March 2013, the Prosecutor filed, confidentially, ex parte, available to the \n" "Prosecutor and Mr Ngudjolo only, the Document in Support of the Appeal. The \n" "Prosecutor filed a confidential redacted version of the Document in Support of the \n" "Appeal on 22 March 2013, and a public redacted version of the Document in Support \n" "of the Appeal on 3 April 2013. In the redacted version of the Document in Support of \n" "the Appeal, the Prosecutor’s entire third ground of appeal was redacted. \n") matches = re.finditer(regex, test_str, re.MULTILINE | re.DOTALL) 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