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"
"
gm

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"http://www\.xinhuanet\.com/yuqing/([0-9]*)-([0-9]*)/([0-9]*)/([a-z])_([0-9]*)\.htm" test_str = ("</li>\n" "<li class=\"clearfix\">\n" "<h3><a href=\"http://www.xinhuanet.com/yuqing/2015-10/25/c_128355180.htm\" target=\"_blank\">张志安：优秀微信公众号发展离不开这12个字</a></h3>\n" "<i class=\"imgs\"><a href=\"http://www.xinhuanet.com/yuqing/2015-10/25/c_128355180.htm\" targrt=\"_blank\"><img class=\"lazyload\" src=\"http://www.news.cn/images2014/xh_load.gif\" data-original=\"\" /></a></i>\n" "<p class=\"summary\">移动互联网的本质是通过便利的方式将内容连接起来，而优秀微信公众号正是用内容和服务在社群之间建立连接。回归一个起点，一个基本的逻辑，一个人有怎样的风格，这个人所带领的团队，所运营的微信公众号就有怎样的风格，风格是价值观的直接体现，也是这个公众号可持续发展的关键。</p>\n" "<div class=\"info\">\n" "<div class=\"bdsharebuttonbox clearfix\"> </div>\n" "<span class=\"time\">2015-10-25</span>\n" "</div>\n") matches = re.finditer(regex, test_str, re.MULTILINE) 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