Help:Regular expressions

A regular expression (regex) is a sequence of characters defining a search pattern. On the wiki, they are commonly used for finding and replacing text through Special:ReplaceText (staff only), AutoWikiBrowser, Pywikibot, or Scribunto/Lua modules.

Each tool/programming language uses its own ruleset for regular expressions:
 * Special:ReplaceText supports a small subset of the PHP and MySQL/PostgreSQL regular-expression set.
 * AutoWikiBrowser uses .NET regular expressions.
 * Pywikibot uses Python regular expressions.
 * Lua/Scribunto pattern are similar to regular expressions, but not identical. See this page for a list of differences.

If you need help with regular expressions, you may post on the talk page, or join the Nookipedia Discord and ask in the #wiki-tech channel.

Testing
There are several online tools to test our patterns. A small selection is listed below.
 * regex101.com
 * regexr.com
 * extendsclass.com
 * softwium.com

Examples
Below is a list of examples of regular expressions that may help you on the wiki. Feel free to expand this list.


 * Replacing instances of  with   (Python):
 * Find:
 * Replace:


 * Matching a multi-line Foreignname template and adding a new "See also" section after it (Python):
 * Find:
 * Replace:


 * Add  parameters after each   parameter in instances of house templates; the template takes in the furniture name as a parameter and returns a filename (AWB):
 * Find:
 * Replace:


 * Prepend an  selector to every CSS property in a stylesheet (source on StackOverflow by Ryan Worth):
 * Find:
 * Replace: