Don't try to parse non-flags as retained pipeline options.

[robertwb]

This can happen if a user passes flags like --foo --bar some_non_flag_arg.

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[robertwb]

R: @ahmedabu98

[github-actions]

Stopping reviewer notifications for this pull request: review requested by someone other than the bot, ceding control

[robertwb]

Flake in PortableRunnerTestWithSubprocesses.test_pardo_timers

[robertwb]

Run Python PreCommit

[codecov]

Codecov Report

Merging #22276 (72bf1a2) into master (67e6726) will decrease coverage by 0.01%.
The diff coverage is 50.00%.

@@            Coverage Diff             @@
##           master   #22276      +/-   ##
==========================================
- Coverage   74.26%   74.24%   -0.02%     
==========================================
  Files         702      702              
  Lines       93019    93022       +3     
==========================================
- Hits        69076    69066      -10     
- Misses      22676    22689      +13     
  Partials     1267     1267              

Flag	Coverage Δ
python	83.62% <50.00%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...dks/python/apache_beam/options/pipeline_options.py	94.34% <50.00%> (-0.42%)	⬇️
.../python/apache_beam/testing/test_stream_service.py	88.09% <0.00%> (-4.77%)	⬇️
sdks/python/apache_beam/io/source_test_utils.py	88.01% <0.00%> (-1.39%)	⬇️
...che_beam/runners/interactive/interactive_runner.py	90.06% <0.00%> (-1.33%)	⬇️
...hon/apache_beam/runners/direct/test_stream_impl.py	93.28% <0.00%> (-0.75%)	⬇️
sdks/python/apache_beam/runners/direct/executor.py	96.46% <0.00%> (-0.55%)	⬇️
sdks/python/apache_beam/transforms/combiners.py	93.05% <0.00%> (-0.39%)	⬇️
...hon/apache_beam/runners/worker/bundle_processor.py	93.54% <0.00%> (+0.12%)	⬆️

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[ahmedabu98]

should we start looking at i+1?

[robertwb]

We will look at i+1, which will be a fresh argument, in the next iteration of the loop.

[ahmedabu98]

Left one comment, otherwise LGTM!