Is there any way to write code for the web without a python framework?

Question

I find python a very interesting language. And as I develop for web, I would like to use it for this purpose. I know there are good frameworks like Flask and Django.

But if I wanted to write small codes just for testing, there would be some way to do this in python without using web frameworks?

For example, in PHP I can create a simple script:

echo "Hello, World"

And then turn on the command line:

php -S localhost:8000

This would create a simple server and run my "hello world".

You can do it in Python?

Answer 1

First, Python is a completely different language from PHP. Although the PHP documentation says that this language is general purpose, it is undeniable that it is highly related to developing scripts to be run on a web server.

In contrast, Python is a language that, among many other things, can also be used for web application development. However, due to this plurality of applications, developing web applications done purely with Python is a quite complex task (as opposed to its simple).

Having made the introduction, my answer to your question is nay, is not possible. The tovmeod response, as far as I know, only allows you to start a web server to manage static files and not to run scripts in Python.

Following his approach, and, as I suggested in the comments, you can run scripts in Python as if it were a CGI script. So, to make your simple "hello world" in Python you need:

1. Create a directory to serve your files.
2. Inside this directory, create a subdirectory called cgi-bin

3. There, create a python module called hello.py with the following content

   #!/usr/bin/env python
   print("""Content-type: text/html
   
   Hello world from Python!""")
   

4. Change file permissions to be executable

5. Start the server with the option to serve CGI scripts:

   python -m http.server --cgi 8000
   

6. Visit localhost:8000/cgi-bin/hello.py and you’re done.

Note that, in this approach, it is necessary to define the Content-type header because, otherwise, the browser might not understand and you will download the script instead of running it. The same goes for the shebang on the first line.

Note that with this same approach, you can also run scripts in PHP, just by changing the shebang.

Another possibility is, instead of creating a root directory to run the Python server, use Apache’s own cgi-bin folder (if you’re using it and it’s configured to handle CGI). That might make things a little simpler. As said in the commentary, you can use the cgi and cgitb library, which can simplify your life a little.

But anyway, my point is, you’re hardly going to create a web application with Python using these approaches. Frameworks like Django and Flask are there for simplify web development. In your specific case, doing a hello world with Flask would be much more simple:

1. Install the flask pip install flask

2. Create the hello.py file anywhere with the following content:

   from flask import Flask
   
   app = Flask(__name__)
   
   @app.route('/')
   def hello():
       return 'hello from flask'
   
   if __name__ == '__main__':
       app.run()
   

3. Run the script python hello.py

4. Visit localhost:5000 and ready.

That way you didn’t have to set up a directory structure, didn’t have to deal with shebangs, didn’t have to change file permissions and didn’t have to deal with HTTP headers.

Okay, it’s 10 lines of Python, with Developer and everything, but try testing a POST using only Python and CGI and then testing a POST with Flask. I say this because I believe you will not test only "echo hello Worlds"...

Answer 2

Yes, you can use the module SimpleHTTPServer.

You can rotate simply:

python -m SimpleHTTPServer 8000

or put this in your code:

import SimpleHTTPServer
import SocketServer

PORT = 8000

Handler = SimpleHTTPServer.SimpleHTTPRequestHandler

httpd = SocketServer.TCPServer(("", PORT), Handler)

print("serving at port", PORT)
httpd.serve_forever()

see: https://docs.python.org/2/library/simplehttpserver.html

If you are using Python 3, the module is now called http.server, the examples are similar:

spin:

python -m http.server 8000

or add inside your code:

import http.server
import socketserver

PORT = 8000

Handler = http.server.SimpleHTTPRequestHandler

httpd = socketserver.TCPServer(("", PORT), Handler)

print("serving at port", PORT)
httpd.serve_forever()

see more in:

https://docs.python.org/3.4/library/http.server.html