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How to Mock Click CLI App Subcommands in Python

Simulate Click-style CLI subcommand calls in Python by using argparse with subparsers and mocking sys.argv in tests or scripts.

cli argparse mocking
Python 
import sys
import argparse


def do_greet(args):
    print(f"Hello, {args.name}!")


def do_goodbye(args):
    print(f"Goodbye, {args.name}!")


def main():
    parser = argparse.ArgumentParser(prog="clickapp")
    subparsers = parser.add_subparsers(dest="command", required=True)

    greet_parser = subparsers.add_par…
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