Switch from getopt to argparse

[pinotree]

getopt is a low-level module for command line handling, and requires manual boilerplate to work. Instead, migrate to argparse, which is more high-level and provides a number of facilities:

• a single place to define each option
• streamlined help texts
• enforcing of mandatory options
• enforcing a value as certain type, or in a list of allowed values

[gapan]

I'm mostly OK with this. However, one thing that I find I prefer with getopt, is that if you type just xdgmenumaker, you get the full help text, along with a message that -f is needed. Now, with argparse, you only get this:

usage: xdgmenumaker [OPTIONS]
xdgmenumaker: error: the following arguments are required: -f/--format

I think this is probably why I went with getopt in the first place.

[pinotree]

Not trying to undermine your feedback on this: how important is that you get the full help text on missing -f? At least from my experience, I have not seen that commonly in other CLI applications; even for xdgmenumaker itself, the users hopefully will either read the man page or the --help text on their own, and remember that in the next usages.

[gapan]

I will turn the question around: how important is to switch parsing methods? Both work fine, so why go into the trouble, if the current one offers more flexibility too?

[pinotree]

getopt is a low level method, and and such it leaves a lot to implemented by the applications:

• the help text has to be manually provided by the user, and kept updated accordingly
• there is a complete duplication of the short and long options in both the getopt call and the checks for the matched option, which means that a mere typo can make an option never used in practice
• enforcing a certain type (like an integer) is left to the user; in this case there is only one, will add more boilerplate in case a new one is added
• enforcing a certain value is only among a fixed choice is left to the user
• the logic for default values is left to the user

In the end, it's much easier and less error-prone to use argparse; even the old and long-deprecated optparse is still a better choice than using getopt manually.

[gapan]

Could you possibly look into this, so we can have the help message on error too?
https://stackoverflow.com/questions/4042452/display-help-message-with-python-argparse-when-script-is-called-without-any-argu#4042861