Python command line interaction library?

Question

I want to develop a small Python app that interacts with the user via the console/command line. Are there any good libraries I can use to get user input and display the output in a nice-looking way? I tried searching but most of what I found was command-line argument processing, didn't see anything about user interaction in the shell.

It should be crossplatform (Windows and Linux)

Answer 1

A really excellent library is cmd which is part of the python standard library. It is cross platform Windows, Linux, Mac. You just have to implement one class and it offers so many great features:

1. provides list of supported commands(they end up being implemented as methods)
2. help command that can be called to explain one of your commands
3. handles the whole entering a command, checking syntax, and calling your method command loop cycle.
4. users can save the commands they have run in an interactive session and run them as a script. check out the example below.

If you take the turtle shell example and save it as turtleshell.py and save the below turtle script file as circles.txt

circle 20
circle 50
circle 100
bye

then you could run the turtle script with the following command:

cat circles.txt | ./turtleshell.py

so in the simple example shown in the docs the developer has essentially made a simple mini-language that can be used as an easier interface to to the turtle module making it even easier to introduce programming to kids. The examples above have been taken from the python3 docs because they have included a detailed example in their docs which wasn't there in the 2.7 docs, but cmd is available and fully functional in python 2.3 and later.