(#123) Fixed beam not being able to access global namespace. (#124)

Also fixed related bug where save_main_session arg for run() wasn't doing anything.

weather_dl/download_pipeline/pipeline.py

@@ -76,15 +76,17 @@ class PipelineArgs:
 
 def pipeline(args: PipelineArgs) -> None:
     """Main pipeline entrypoint."""
+    import builtins
+    import typing as t
     logger.info(f"Using '{args.num_requesters_per_key}' requests per subsection (license).")
 
     subsections = get_subsections(args.config)
 
     request_idxs = {name: itertools.cycle(range(args.num_requesters_per_key)) for name, _ in subsections}
 
     def subsection_and_request(it: Config) -> t.Tuple[str, int]:
-        subsection = t.cast(str, it.get('parameters', {}).get('__subsection__', 'default'))
-        return subsection, next(request_idxs[subsection])
+        subsection = t.cast(builtins.str, it.get('parameters', {}).get('__subsection__', 'default'))
+        return subsection, builtins.next(request_idxs[subsection])
 
     subsections_cycle = itertools.cycle(subsections)
 
@@ -135,7 +137,8 @@ def run(argv: t.List[str], save_main_session: bool = True) -> PipelineArgs:
 
     # We use the save_main_session option because one or more DoFn's in this
     # workflow rely on global context (e.g., a module imported at module level).
-    pipeline_options = PipelineOptions(pipeline_args + '--save_main_session True'.split())
+    save_main_session_args = ['--save_main_session'] + ['True' if save_main_session else 'False']
+    pipeline_options = PipelineOptions(pipeline_args + save_main_session_args)
 
     client_name = config['parameters']['client']
     store = None  # will default to using FileSystems()