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

/
/
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"<b>(.*?)<\/b>" test_str = ("<b> GALADRIEL (V.O.)\n" "</b> (Elvish: subtitled)\n" " \"I amar prestar sen: han mathon ne nen,\n" " han mathon ne chae...a han noston ned\n" " wilith.\"\n" " (English:)\n" " The world is changed: I feel it in the\n" " water, I feel it in the earth, I smell it\n" " in the air...Much that once was is lost,\n" " for none now live who remember it.\n\n" "<b>SUPER: THE LORD OF THE RINGS\n" "</b>\n" "<b>EXT. PROLOGUE -- DAY\n" "</b>\n" "IMAGE: FLICKERING FIRELIGHT. The NOLDORIN FORGE in EREGION.\n" "MOLTEN GOLD POURS from the lip of an IRON LADLE.\n\n" "<b> GALADRIEL (V.O.)\n" "</b> It began with the forging of the Great\n" " Rings.\n\n" "IMAGE: THREE RINGS, each set with a single GEM, are received\n" "by the HIGH ELVES-GALADRIEL, GIL-GALAD and CIRDAN.\n\n" "<b> GALADRIEL (V.O.) (CONT'D)\n" "</b> Three were given to the Elves, immortal,\n" " wisest...fairest of all beings.\n\n" "IMAGE: SEVEN RINGS held aloft in triumph by the DWARF LORDS.\n\n" "<b> GALADRIEL (V.O.) (CONT'D)\n" "</b> Seven to the Dwarf Lords, great miners\n" " and craftsmen of the mountain halls.\n\n" "IMAGE: NINE RINGS clutched tightly by the KINGS OF MEN...as\n" "if holding-close a precious secret.\n\n" "<b> GALADRIEL (V.O.) (CONT'D)\n" "</b> And Nine...nine rings were gifted to the\n" " race of Men who, above all else, desire\n" " power.\n" "<b> (MORE)\n" "</b>") 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