+ """
+ global config_parse_called
+ if config_parse_called:
+ return config
+
+ global saved_messages
+
+ # If we're about to do the usage message dump, put the main module's
+ # argument group last in the list (if possible) so that when the user
+ # passes -h or --help, it will be visible on the screen w/o scrolling.
+ reordered_action_groups = []
+ global prog
+ for arg in sys.argv:
+ if arg == '--help' or arg == '-h':
+ for group in args._action_groups:
+ if entry_module is not None and entry_module in group.title:
+ reordered_action_groups.append(group)
+ elif program_name in group.title:
+ reordered_action_groups.append(group)
+ else:
+ reordered_action_groups.insert(0, group)
+ args._action_groups = reordered_action_groups
+
+ # Examine the environment for variables that match known flags.
+ # For a flag called --example_flag the corresponding environment
+ # variable would be called EXAMPLE_FLAG.
+ usage_message = args.format_usage()
+ optional = False
+ var = ''
+ for x in usage_message.split():
+ if x[0] == '[':
+ optional = True
+ if optional:
+ var += f'{x} '
+ if x[-1] == ']':
+ optional = False
+ var = var.strip()
+ var = var.strip('[')
+ var = var.strip(']')
+ chunks = var.split()
+ if len(chunks) > 1:
+ var = var.split()[0]
+
+ # Environment vars the same as flag names without
+ # the initial -'s and in UPPERCASE.
+ env = var.strip('-').upper()
+ if env in os.environ:
+ if not is_flag_already_in_argv(var):
+ value = os.environ[env]
+ saved_messages.append(
+ f'Initialized from environment: {var} = {value}'
+ )
+ from string_utils import to_bool
+ if len(chunks) == 1 and to_bool(value):
+ sys.argv.append(var)
+ elif len(chunks) > 1:
+ sys.argv.append(var)
+ sys.argv.append(value)
+ var = ''
+ env = ''
+ else:
+ next
+
+ # Look for loadfile and read/parse it if present.
+ loadfile = None
+ saw_other_args = False
+ grab_next_arg = False
+ for arg in sys.argv[1:]:
+ if 'config_loadfile' in arg:
+ pieces = arg.split('=')
+ if len(pieces) > 1:
+ loadfile = pieces[1]
+ else:
+ grab_next_arg = True
+ elif grab_next_arg:
+ loadfile = arg
+ else:
+ saw_other_args = True
+
+ if loadfile is not None:
+ if saw_other_args:
+ msg = f'Augmenting commandline arguments with those from {loadfile}.'
+ print(msg, file=sys.stderr)
+ saved_messages.append(msg)
+ if not os.path.exists(loadfile):
+ print(f'ERROR: --config_loadfile argument must be a file, {loadfile} not found.',
+ file=sys.stderr)
+ sys.exit(-1)
+ with open(loadfile, 'r') as rf:
+ newargs = rf.readlines()
+ newargs = [arg.strip('\n') for arg in newargs if 'config_savefile' not in arg]
+ sys.argv += newargs
+
+ # Parse (possibly augmented, possibly completely overwritten)
+ # commandline args with argparse normally and populate config.
+ known, unknown = args.parse_known_args()
+ config.update(vars(known))
+
+ # Reconstruct the argv with unrecognized flags for the benefit of
+ # future argument parsers. For example, unittest_main in python
+ # has some of its own flags. If we didn't recognize it, maybe
+ # someone else will.
+ if len(unknown) > 0:
+ if config['config_rejects_unrecognized_arguments']:
+ raise Exception(
+ f'Encountered unrecognized config argument(s) {unknown} with --config_rejects_unrecognized_arguments enabled; halting.'
+ )
+ saved_messages.append(f'Config encountered unrecognized commandline arguments: {unknown}')
+ sys.argv = sys.argv[:1] + unknown
+
+ # Check for savefile and populate it if requested.
+ savefile = config['config_savefile']
+ if savefile and len(savefile) > 0:
+ with open(savefile, 'w') as wf:
+ wf.write(
+ "\n".join(original_argv[1:])
+ )
+
+ # Also dump the config on stderr if requested.