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Pure-Python Web Servers

A fun way to demonstrate that Python comes with “batteries included” is to enter a directory on your system and run the SimpleHTTPServer Standard Library module as a stand-alone program:

root@erlerobot:~/Python_files# python -m SimpleHTTPServer
Serving HTTP on port 8000 ...

If you direct your browser to localhost:8000, you will see the contents of this script's current directory displayed for browsing, such as the listings provided by Apache when a site leaves a directory browsable. Documents and images will load in your web browser when selected, based on the content types chosen through the best guesses of the mimetypes Standard Library module. The mimetypes module converts between a filename or URL and the MIME type associated with the filename extension. Conversions are provided from filename to MIME type and from MIME type to filename extension; encodings are not supported for the latter conversion.

Yoday, we use namespaces, callables, and duck-typed objects to provide much cleaner forms of extensibility. For example, today an object like start_response is provided as an argument (dependency injection), and the WSGI standard specifies its behavior rather than its inheritance tree (duck typing).The Standard Library includes two other HTTP servers:

  • SimpleXMLRPCServer and DocXMLRPCServer each provide a server endpoint against which client programs can make XML-RPC remote procedure calls. This protocol uses XML files submitted through HTTP requests.

Note that none of the preceding servers is typically intended for production use; instead, they are useful for small internal tasks for which you just need a quick HTTP endpoint to be used by other services internal to a system or subnet. And while most Python web frameworks will provide a way to run your application from the command line for debugging. These pure-Python web servers can be very useful if you are writing an application that users will be installing locally, and you want to provide a web interface without having to ship a separate web server like Apache or nginx.