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

@
@
gmis

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"<a[^>]*href=\"(?<url>[^\"]*(?<=\?|&)o=(?<number>\d+)[^\"]*)\"[^>]*>\s*last" test_str = ("<div class=\"listing_thumbs_resultcontainer\">\n" " \n" " <span class=\"FloatLeft nav-next-btn\">\n" " \n" " \n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=1&amp;q=nike air&amp;th=1\" title=\"Go to first page\">« First</a>\n" " \n\n" " \n" " <span class=\"nav-next-btn nohistory marginLeft\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=18&amp;q=nike air&amp;th=1\" title=\"Go to previous page\">\n" " ‹ Previous\n" " </a>\n" " </span>\n" " &nbsp; \n" " \n" " \n\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=1&amp;q=nike air&amp;th=1\" title=\"Page 1 of 29\">1</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=2&amp;q=nike air&amp;th=1\" title=\"Page 2 of 29\">2</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=3&amp;q=nike air&amp;th=1\" title=\"Page 3 of 29\">3</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=4&amp;q=nike air&amp;th=1\" title=\"Page 4 of 29\">4</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=5&amp;q=nike air&amp;th=1\" title=\"Page 5 of 29\">5</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=6&amp;q=nike air&amp;th=1\" title=\"Page 6 of 29\">6</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=7&amp;q=nike air&amp;th=1\" title=\"Page 7 of 29\">7</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=8&amp;q=nike air&amp;th=1\" title=\"Page 8 of 29\">8</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=9&amp;q=nike air&amp;th=1\" title=\"Page 9 of 29\">9</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=10&amp;q=nike air&amp;th=1\" title=\"Page 10 of 29\">10</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=11&amp;q=nike air&amp;th=1\" title=\"Page 11 of 29\">11</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=12&amp;q=nike air&amp;th=1\" title=\"Page 12 of 29\">12</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=13&amp;q=nike air&amp;th=1\" title=\"Page 13 of 29\">13</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=14&amp;q=nike air&amp;th=1\" title=\"Page 14 of 29\">14</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=15&amp;q=nike air&amp;th=1\" title=\"Page 15 of 29\">15</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=16&amp;q=nike air&amp;th=1\" title=\"Page 16 of 29\">16</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=17&amp;q=nike air&amp;th=1\" title=\"Page 17 of 29\">17</a>\n" " </span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=18&amp;q=nike air&amp;th=1\" title=\"Page 18 of 29\">18</a>\n" " </span>\n" " \n" " <span class=\"nav-active\"><strong>19</strong></span>\n" " <span class=\"non-active nohistory\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=20&amp;q=nike air&amp;th=1\" title=\"Page 20 of 29\">20</a>\n" " </span\n" " \n" " \n" " </span>\n" " \n" " <span class=\"nav-next-btn nohistory FloatRight\">\n" " \n" " <span class=\"nav-next-btn nohistory marginRight\">\n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=20&amp;q=nike air&amp;th=1\" title=\"Go to next page\">\n" " Next ›\n" " </a>\n" " </span>\n" " \n" " \n" " \n" " \n" " <a href=\"http://www.mudah.my/Malaysia/nike+air-for-sale?o=29&amp;q=nike air&amp;th=1\" title=\"Go to last page\">\n" " Last »\n" " </a>\n" " \n" " \n" " </span> \n" " \n" " </div>") matches = re.finditer(regex, test_str, re.MULTILINE | re.IGNORECASE | 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