parsing both Python and click command line options

Question

Often I want to profile a CLI program built with Click, but I can't figure out how to parse both the Python command line options and the click command line options/arguments. For example, if my script took a single option and two arguments, I can run it fine like:

python add.py --verbose 1 2

Similarly, when I profile a simple (non-Click) script, I can do this:

python -m cProfile -o stats.txt add_no_click.py 1 2

but when I want to profile the Click script, I get this:

python -m cProfile -o stats.txt add.py --verbose 1 2
Error: no such option: -o

I know I must be missing some documentation out there. For what it's worth, I'm using Python 2.7 on Windows 10 64-bit, although I doubt it has a bearing on the answer.

python 2 does not recognize the '-o' option. Why are you surprised? — DYZ
@DYZ, when '-o' is used in conjunction with the cProfile module, it specifies the output file to write the profile results, .e.g python -m cProfile [-o output_file] [-s sort_order] myscript.py cProfile docs — grovduck

grovduck grovduck · Accepted Answer · 2018-01-26T21:22:33

Sorry for the self-answer, but hope this might help others. The stupid thing I did (and that I didn't show in the question above) was forgetting to call main with just sys.argv[1:].

Sample program:

import click

@click.command()
@click.option('-v', '--verbose', is_flag=True)
@click.argument('a', type=click.INT, required=True)
@click.argument('b', type=click.INT, required=True)
def main(verbose, a, b):
    if verbose:
        print('The answer is {}'.format(a + b))
    else:
        print(a + b)

if __name__ == '__main__':
    import sys
    main(sys.argv[1:])

Running it:

> python -m cProfile -o foo.stats add.py --verbose 1 2
The answer is 3

and the profile information is written to foo.stats.

parsing both Python and click command line options

1 Answers