add python testing_cli_argparse example

Author: rkm

python/README.md

@@ -0,0 +1,3 @@
+# Python Snippets
+
+-   [Testing with argparse](./testing_cli_argparse)

python/testing_cli_argparse/__pycache__/script.cpython-38.pyc

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+import argparse
+from typing import Optional
+from typing import Sequence
+
+
+def main(argv: Optional[Sequence[str]] = None) -> int:
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument("first")
+
+    args = parser.parse_args(argv)
+
+    return 0 if args.first == "foo" else 1
+
+
+if __name__ == "__main__":
+    exit(main())

python/testing_cli_argparse/script.py

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+from script import main
+
+
+def test_main() -> None:
+    assert main(["foo"]) == 0, "Expected foo to return 0"
+    assert main(["bar"]) == 1, "Expected bar to return 1"
+
+
+test_main()