Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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

`
`
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"(?s:(\"name\" : \"(.*?)\".*?作者[:]*</span>[:]*.*?>(.*?)<.*?出版社.*?> (.*?)<.*?>出版年.*?([\d]{4}-[\d]).*?定价:</span> (.*?)<.*?ISBN:</span> (.*?)<.*?v:average\"> ([\d].[\d]).*?v:votes\">([\d]+?)<.*?\"rating_per\">(.*?)<.*?\"rating_per\">(.*?)<.*?\"rating_per\">(.*?)<.*?\"rating_per\">(.*?)<.*?\"rating_per\">(.*?)<))" test_str = ("\n" "<script type=\"application/ld+json\">\n" "{\n" " \"@context\":\"http://schema.org\",\n" " \"@type\":\"Book\",\n" " \"workExample\": [],\n" " \"name\" : \"索拉里斯星\",\n\n" " <span class=\"pl\"> 作者</span>:\n" " \n" " \n" " <a class=\"\" href=\"/search/%E6%96%AF%E5%9D%A6%E5%B0%BC%E6%96%AF%E7%93%A6%E5%A4%AB%C2%B7%E8%8E%B1%E5%A7%86\">[波] 斯坦尼斯瓦夫·莱姆</a>\n" " </span><br/>\n\n" " \n" " \n" " \n" " <span class=\"pl\">出版社:</span> 译林出版社<br/>\n\n" " \n" " \n" " \n\n" " \n" " \n" " \n\n" " \n" " \n" " \n" " <span class=\"pl\">原作名:</span> Solaris<br/>\n\n" " \n" " \n" " \n" " <span>\n" " <span class=\"pl\"> 译者</span>:\n" " \n" " \n" " <a class=\"\" href=\"/search/%E9%9D%96%E6%8C%AF%E5%BF%A0\">靖振忠</a>\n" " </span><br/>\n\n" " \n" " \n" " \n" " <span class=\"pl\">出版年:</span> 2021-8<br/>\n\n" " \n" " \n" " \n" " <span class=\"pl\">页数:</span> 254<br/>\n\n" " \n" " \n" " \n" " <span class=\"pl\">定价:</span> 49.00元<br/>\n\n" " \n" " \n" " \n" " <span class=\"pl\">装帧:</span> 平装<br/>\n\n" " \n" " \n" " \n" " <span class=\"pl\">丛书:</span>&nbsp;<a href=\"https://book.douban.com/series/54333\">译林幻系列</a><br>\n\n" " \n" " \n" " \n" " \n" " \n" " <span class=\"pl\">ISBN:</span> 9787544782173<br/>\n\n" " \n" " \n" " \n\n\n" "</div>\n\n" "</div>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n" " \n\n\n\n\n\n" "<div id=\"interest_sectl\" class=\"\">\n" " <div class=\"rating_wrap clearbox\" rel=\"v:rating\">\n" " <div class=\"rating_logo\">豆瓣评分</div>\n" " <div class=\"rating_self clearfix\" typeof=\"v:Rating\">\n" " <strong class=\"ll rating_num \" property=\"v:average\"> 8.7 </strong>\n" " <span property=\"v:best\" content=\"10.0\"></span>\n" " <div class=\"rating_right \">\n" " <div class=\"ll bigstar45\"></div>\n" " <div class=\"rating_sum\">\n" " <span class=\"\">\n" " <a href=\"comments\" class=\"rating_people\"><span property=\"v:votes\">8085</span>人评价</a>\n" " </span>\n" " </div>\n\n\n" " </div>\n" " </div>\n" " \n" " \n" " \n" "<span class=\"stars5 starstop\" title=\"力荐\">\n" " 5星\n" "</span>\n\n" " \n" "<div class=\"power\" style=\"width:64px\"></div>\n\n" " <span class=\"rating_per\">46.0%</span>\n" " <br>\n" " \n" " \n" "<span class=\"stars4 starstop\" title=\"推荐\">\n" " 4星\n" "</span>\n\n" " \n" "<div class=\"power\" style=\"width:54px\"></div>\n\n" " <span class=\"rating_per\">39.4%</span>\n" " <br>\n" " \n" " \n" "<span class=\"stars3 starstop\" title=\"还行\">\n" " 3星\n" "</span>\n\n" " \n" "<div class=\"power\" style=\"width:17px\"></div>\n\n" " <span class=\"rating_per\">12.5%</span>\n" " <br>\n" " \n" " \n" "<span class=\"stars2 starstop\" title=\"较差\">\n" " 2星\n" "</span>\n\n" " \n" "<div class=\"power\" style=\"width:2px\"></div>\n\n" " <span class=\"rating_per\">1.8%</span>\n" " <br>\n" " \n" " \n" "<span class=\"stars1 starstop\" title=\"很差\">\n" " 1星\n" "</span>\n\n" " \n" "<div class=\"power\" style=\"width:0px\"></div>\n\n" " <span class=\"rating_per\">0.3%</span>\n\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