There are many times when a task calls for a simple python script. It is usually something small that takes some input file as a parameter, does some processing, and then spits out some results. It might even take an options or two. It’s tempting to just throw some lines of code into a file and be done with it. This may work but often just makes things more difficult later.
Consider the following code (let’s creatively call it
which simply converts the input to uppercase:
What happens, however, when it grows a little bit and we add a function?
What happens if we want to include that function into another file? Then importing do_stuff.py will cause the for loop to run. A much better solution is to do all of the ‘scripty’ stuff in a main function that only gets called if the file is called as a script (as opposed to being imported as a library):
That’s a lot of code for a simple task. Well it doesn’t necessarily require
much typing to enter thanks to the
SnipMate plugin for
vim. By adding the following code in
~/.vim/snippets/python.snippets we can
create almost all of the code by typing
start and hitting tab right
at the beginning of the script.
This will create the main function and position the cursor within the
thus making it a snap to write some quick documentation of what this script will do.
num_args variable is there to make sure the user enters the right number of
arguments. Otherwise the script exits with an error. The rest of the processing code
should go directly after the
if statement. When scripts are written in this manner,
they can be painlessly turned into libraries at a future point in time.