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

%
%
msix

Test String

Code Generator

Generated Code

# coding=utf8 # the above tag defines encoding for this document and is for Python 2.x compatibility import re regex = r""" <div\b # Start of outer DIV start tag. [^>]*? # Lazily match up to id attrib. \bclass\s*+=\s*+ # id attribute name and = ([\'"]?+) # $1: Optional quote delimiter. \basd\b # specific ID to be matched. (?(1)\1) # If open quote, match same closing quote [^>]*+> # remaining outer DIV start tag. ( # $2: DIV contents. (may be called recursively!) (?: # Non-capture group for DIV contents alternatives. # DIV contents option 1: All non-DIV, non-comment stuff... [^<]++ # One or more non-tag, non-comment characters. # DIV contents option 2: Start of a non-DIV tag... | < # Match a "<", but only if it (?! # is not the beginning of either /?div\b # a DIV start or end tag, | !-- # or an HTML comment. ) # Ok, that < was not a DIV or comment. # DIV contents Option 3: an HTML comment. | <!--.*?--> # A non-SGML compliant HTML comment. # DIV contents Option 4: a nested DIV element! | <div\b[^>]*+> # Inner DIV element start tag. (?2) # Recurse group 2 as a nested subroutine. </div\s*> # Inner DIV element end tag. )*+ # Zero or more of these contents alternatives. ) # End 2$: DIV contents. </div\s*> """ test_str = ("<div>\n" " <div class=\"asd\">\n" " <div>\n" " <div>\n" " Hello\n" " </div>\n" " </div>\n" " </div>\n" "</div>") matches = re.search(regex, test_str, re.MULTILINE | re.DOTALL | re.IGNORECASE | re.VERBOSE) if matches: print ("Match was found at {start}-{end}: {match}".format(start = matches.start(), end = matches.end(), match = matches.group())) for groupNum in range(0, len(matches.groups())): groupNum = groupNum + 1 print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = matches.start(groupNum), end = matches.end(groupNum), group = matches.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