pyperf is incompatible with click

When a script calls pyperf.Runner.bench_func from a script that uses click to handle arguments, it raises an exception in pyperf's argument parsing logic. Here is a minimal reproducing script:

import click
import pyperf

@click.command()
def cli():
    def f():
        pass

    runner = pyperf.Runner()

    runner.bench_func("Example", f)

if __name__ == "__main__":
    cli()

Here's a requirements.txt, pinned to the versions I have tried this with:

click==7.1.1
pyperf==2.0.0

The error message is:

$ python my_benchmark.py 
Usage: my_benchmark.py [OPTIONS]
Try 'my_benchmark.py --help' for help.

Error: no such option: --worker

I believe that the issue is that pyperf.Runner is directly using argparse to add its own command line arguments, which is not really the behavior I would expect from a library.

It might be a lot to ask, but I think a better option would be to refactor this into a config object that can also be constructed automatically from the parser, something like this:

import attr

@attr.s(auto_attrib=True)
class RunnerConfig:
    verbose: bool = False
    quiet: bool = False
    pipe: int = None
    ...

    @classmethod
    def from_argparse(cls, argparser=None):
        if argparser is None:
            argparser = argparse.ArgumentParser()
        parser.description = "Benchmark"
        ....
        args = argparser.parse_args()
        return cls(verbose=args.verbose, quiet=args.quiet, pipe=args.pipe, ...)

To avoid backwards incompatibility issues, you can add a flag to Runner like use_argparse=True, which users of click could set to False to avoid this problem.

Run the minimal reproducing script from the issue with click 7.1.1 and pyperf 2.0.0, then inspect pyperf/_runner.py around lines 126-129 where argparse is used. Trace how Runner handles its arguments when invoked inside the click command. Done means the reproduction no longer sends pyperf options such as --worker to click, while the intended benchmark invocation remains supported.