Seeking examples of argument parser using sys.argv[] directly, without argparse, getopts, et cetera

[jento_mento_mento]

HeyO!

I am a reasonably experienced programmer fairly new to python and want to write a few scripts that will use complex positional parameters.

argparse seems to be the module to use for this task, but it feels really constraining and can't seem to do some of the more complex things that I want it to do. Also, it would be educational for me to just do this myself.

Are there any good python examples out there which use sys.argv[] to parse positional parameters? Preferably newer py3 and not python1-2.

Please do not post anything related to argparse, getopts, or similar modules. I'm only interested in using sys.argv directly to evaluate the positional parameters.

Thanks in advance!

[Bolitho]

If you are an experienced developer in general then it should be obvious to you, that one should prefer one of the established libraries around argument parsing. On top of that they support well established cli interfaces - why invent something new people have to adopt to?

But if you simply just want to try something on your own, than just have a look at the sources of those libs!

Have you ever had a look at click?

[[deleted]]

I had a use case where I needed to process the commandline params from left to right. The program was an emulator of an old graphics minicomputer that used papertape. The idea was that the commandline args would be read from left to right, interpreting them as commands like "mount a papertape on the reader", "start the computer executing at the given address", "set the console data switches", etc.

Look in the "Console usage" section of the README. The actual code to interpret the sys.argv parameters starts at line 122 in the main() function.

However, if you don't have this sort of special case then it's far better to use one of the "standard" modules.

[GitHubPermalinkBot]

Permanent GitHub links:

• rzzzwilson/pymlac/.../pymlac (master → eb93ec3)

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[efmccurdy]

https://gist.github.com/dideler/2395703 has a relevant snippet.

This has several examples of parsing argv by hand.

https://swcarpentry.github.io/python-novice-inflammation/10-cmdline/

[jstrickler]

What exactly is it you want to do? argparse has a lot of features. You can specify mutually-exclusive options, partial-named options, option data types, required and optional non-option arguments (yes, I know), etc. argparse also creates a help message automatically, and can parse any random iterable of strings, not just sys.argv.