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

~
~
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*<VirtualHost\s+[^>]*>\s*ServerName\s+(?P<ServerName>\S+)\s*DocumentRoot\s+(?P<DocumentRoot>.+?)\s*</VirtualHost>" test_str = ("# Virtual Hosts\n" "#\n" "# Required modules: mod_log_config\n\n" "# If you want to maintain multiple domains/hostnames on your\n" "# machine you can setup VirtualHost containers for them. Most configurations\n" "# use only name-based virtual hosts so the server doesn\\'t need to worry about\n" "# IP addresses. This is indicated by the asterisks in the directives below.\n" "#\n" "# Please see the documentation at \n" "# <URL:http://httpd.apache.org/docs/2.4/vhosts/>\n" "# for further details before you try to setup virtual hosts.\n" "#\n" "# You may use the command line option \\'-S\\' to verify your virtual host\n" "# configuration.\n\n" "#\n" "# Use name-based virtual hosting.\n" "#\n" "##NameVirtualHost *:80\n" "#\n" "# VirtualHost example:\n" "# Almost any Apache directive may go into a VirtualHost container.\n" "# The first VirtualHost section is used for all requests that do not\n" "# match a ##ServerName or ##ServerAlias in any <VirtualHost> block.\n" "#\n" "##<VirtualHost *:80>\n" " ##ServerAdmin webmaster@dummy-host.example.com\n" " ##DocumentRoot \"D:/xampp/htdocs/dummy-host.example.com\"\n" " ##ServerName dummy-host.example.com\n" " ##ServerAlias www.dummy-host.example.com\n" " ##ErrorLog \"logs/dummy-host.example.com-error.log\"\n" " ##CustomLog \"logs/dummy-host.example.com-access.log\" common\n" "##</VirtualHost>\n\n" "##<VirtualHost *:80>\n" " ##ServerAdmin webmaster@dummy-host2.example.com\n" " ##DocumentRoot \"D:/xampp/htdocs/dummy-host2.example.com\"\n" " ##ServerName dummy-host2.example.com\n" " ##ErrorLog \"logs/dummy-host2.example.com-error.log\"\n" " ##CustomLog \"logs/dummy-host2.example.com-access.log\" common\n" "##</VirtualHost>\n\n\n\n" "##<VirtualHost *:8080>\n" " ##ServerName CI1\n" " ##DocumentRoot D:\\xampp\\htdocs\\codeigniter_1\\public\n" "##</VirtualHost>\n\n" "<VirtualHost *:8080>\n" " ServerName CI2\n" " DocumentRoot D:\\xampp\\htdocs\\codeigniter_2\\public\n" "</VirtualHost>\n\n" "<VirtualHost *:8080>\n" " ServerName CI3\n" " DocumentRoot D:\\xampp\\htdocs\\codeigniter_3\\public\n" "</VirtualHost>\n" "<VirtualHost *:8080>\n" " ServerName CI3\n" " DocumentRoot D:\\Embedded Spaces and spaces at end of line\\htdocs\\codeigniter_3\\public \n" "</VirtualHost>") 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