X-Git-Url: https://wannabe.guru.org/gitweb/?a=blobdiff_plain;f=config.py;h=c7c686d738803484a6ae6277af7fc5ebd25d5056;hb=903843730a9916105352c729e94136a755b5e529;hp=22660cc41c46fc92dba8c32e0caf61c4d5d207c5;hpb=01f7083eeef0330820e0e5d03fb83a3a8bfd2777;p=python_utils.git diff --git a/config.py b/config.py index 22660cc..c7c686d 100644 --- a/config.py +++ b/config.py @@ -1,68 +1,83 @@ #!/usr/bin/env python3 +# © Copyright 2021-2022, Scott Gasch + """Global configuration driven by commandline arguments, environment variables and saved configuration files. This works across several modules. Usage: - module.py: - ---------- - import config - - parser = config.add_commandline_args( - "Module", - "Args related to module doing the thing.", - ) - parser.add_argument( - "--module_do_the_thing", - type=bool, - default=True, - help="Should the module do the thing?" - ) - - main.py: - -------- - import config - - def main() -> None: + In your file.py:: + + import config + parser = config.add_commandline_args( - "Main", - "A program that does the thing.", + "Module", + "Args related to module doing the thing.", ) parser.add_argument( - "--dry_run", + "--module_do_the_thing", type=bool, - default=False, - help="Should we really do the thing?" + default=True, + help="Should the module do the thing?" ) - config.parse() # Very important, this must be invoked! + + In your main.py:: + + import config + + def main() -> None: + parser = config.add_commandline_args( + "Main", + "A program that does the thing.", + ) + parser.add_argument( + "--dry_run", + type=bool, + default=False, + help="Should we really do the thing?" + ) + config.parse() # Very important, this must be invoked! If you set this up and remember to invoke config.parse(), all commandline arguments will play nicely together. This is done automatically for you - if you're using the bootstrap module's initialize wrapper. + if you're using the :meth:`bootstrap.initialize` decorator on + your program's entry point. See :meth:`python_modules.bootstrap.initialize` + for more details.:: + + import bootstrap + + @bootstrap.initialize + def main(): + whatever + + if __name__ == '__main__': + main() + + Either way, you'll get this behavior from the commandline:: - % main.py -h - usage: main.py [-h] - [--module_do_the_thing MODULE_DO_THE_THING] - [--dry_run DRY_RUN] + % main.py -h + usage: main.py [-h] + [--module_do_the_thing MODULE_DO_THE_THING] + [--dry_run DRY_RUN] - Module: - Args related to module doing the thing. + Module: + Args related to module doing the thing. - --module_do_the_thing MODULE_DO_THE_THING - Should the module do the thing? + --module_do_the_thing MODULE_DO_THE_THING + Should the module do the thing? - Main: - A program that does the thing + Main: + A program that does the thing - --dry_run - Should we really do the thing? + --dry_run + Should we really do the thing? Arguments themselves should be accessed via - config.config['arg_name']. e.g. + :code:`config.config['arg_name']`. e.g.:: - if not config.config['dry_run']: - module.do_the_thing() + if not config.config['dry_run']: + module.do_the_thing() """ @@ -77,11 +92,11 @@ from typing import Any, Dict, List, Optional # taking any unnecessary dependencies back on them. # Defer logging messages until later when logging has been initialized. -saved_messages: List[str] = [] +SAVED_MESSAGES: List[str] = [] # Make a copy of the original program arguments. -program_name: str = os.path.basename(sys.argv[0]) -original_argv: List[str] = [arg for arg in sys.argv] +PROGRAM_NAME: str = os.path.basename(sys.argv[0]) +ORIG_ARGV: List[str] = sys.argv.copy() class OptionalRawFormatter(argparse.HelpFormatter): @@ -90,6 +105,33 @@ class OptionalRawFormatter(argparse.HelpFormatter): "RAW|". In that case, the line breaks are preserved and the text is not wrapped. + Use this, for example, when you need the helptext of an argument + to have its spacing preserved exactly, e.g.:: + + args.add_argument( + '--mode', + type=str, + default='PLAY', + choices=['CHEAT', 'AUTOPLAY', 'SELFTEST', 'PRECOMPUTE', 'PLAY'], + metavar='MODE', + help='''RAW|Our mode of operation. One of: + + PLAY = play wordle with me! Pick a random solution or + specify a solution with --template. + + CHEAT = given a --template and, optionally, --letters_in_word + and/or --letters_to_avoid, return the best guess word; + + AUTOPLAY = given a complete word in --template, guess it step + by step showing work; + + SELFTEST = autoplay every possible solution keeping track of + wins/losses and average number of guesses; + + PRECOMPUTE = populate hash table with optimal guesses. + ''', + ) + """ def _split_lines(self, text, width): @@ -99,16 +141,21 @@ class OptionalRawFormatter(argparse.HelpFormatter): # A global parser that we will collect arguments into. -args = argparse.ArgumentParser( +ARGS = argparse.ArgumentParser( description=None, formatter_class=OptionalRawFormatter, fromfile_prefix_chars="@", - epilog=f'{program_name} uses config.py ({__file__}) for global, cross-module configuration setup and parsing.', + epilog=f'{PROGRAM_NAME} uses config.py ({__file__}) for global, cross-module configuration setup and parsing.', + # I don't fully understand why but when loaded by sphinx sometimes + # the same module is loaded many times causing any arguments it + # registers via module-level code to be redefined. Work around + # this iff the program is 'sphinx-build' + conflict_handler='resolve' if PROGRAM_NAME == 'sphinx-build' else 'error', ) # Keep track of if we've been called and prevent being called more # than once. -config_parse_called = False +CONFIG_PARSE_CALLED = False # A global configuration dictionary that will contain parsed arguments. @@ -116,12 +163,21 @@ config_parse_called = False # This is the data that is most interesting to our callers; it will hold # the configuration result. config: Dict[str, Any] = {} + # It would be really nice if this shit worked from interactive python -def add_commandline_args(title: str, description: str = ""): - """Create a new context for arguments and return a handle.""" - return args.add_argument_group(title, description) +def add_commandline_args(title: str, description: str = "") -> argparse._ArgumentGroup: + """Create a new context for arguments and return a handle. + + Args: + title: A title for your module's commandline arguments group. + description: A helpful description of your module. + + Returns: + An argparse._ArgumentGroup to be populated by the caller. + """ + return ARGS.add_argument_group(title, description) group = add_commandline_args( @@ -159,30 +215,74 @@ group.add_argument( ) -def is_flag_already_in_argv(var: str): - """Is a particular flag passed on the commandline?""" +def overwrite_argparse_epilog(msg: str) -> None: + """Allows your code to override the default epilog created by + argparse. + + Args: + msg: The epilog message to substitute for the default. + """ + ARGS.epilog = msg + + +def is_flag_already_in_argv(var: str) -> bool: + """Returns true if a particular flag is passed on the commandline? + + Args: + var: The flag to search for. + """ for _ in sys.argv: if var in _: return True return False -def reorder_arg_action_groups(entry_module: Optional[str]): - global program_name, args +def _reorder_arg_action_groups_before_help(entry_module: Optional[str]): + """Internal. Used to reorder the arguments before dumping out a + generated help string such that the main program's arguments come + last. + + """ reordered_action_groups = [] - for group in args._action_groups: - if entry_module is not None and entry_module in group.title: # type: ignore - reordered_action_groups.append(group) - elif program_name in group.title: # type: ignore - reordered_action_groups.append(group) + for grp in ARGS._action_groups: + if entry_module is not None and entry_module in grp.title: # type: ignore + reordered_action_groups.append(grp) + elif PROGRAM_NAME in group.title: # type: ignore + reordered_action_groups.append(grp) else: - reordered_action_groups.insert(0, group) + reordered_action_groups.insert(0, grp) return reordered_action_groups -def augment_sys_argv_from_environment_variables(): - global saved_messages - usage_message = args.format_usage() +def print_usage() -> None: + """Prints the normal help usage message out.""" + ARGS.print_help() + + +def usage() -> str: + """ + Returns: + program usage help text as a string. + """ + return ARGS.format_usage() + + +def _augment_sys_argv_from_environment_variables(): + """Internal. Look at the system environment for variables that match + arg names. This is done via some munging such that: + + :code:`--argument_to_match` + + ...is matched by: + + :code:`ARGUMENT_TO_MATCH` + + This allows programmers to set args via shell environment variables + in lieu of passing them on the cmdline. + + """ + + usage_message = usage() optional = False var = '' for x in usage_message.split(): @@ -205,7 +305,7 @@ def augment_sys_argv_from_environment_variables(): 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}') + SAVED_MESSAGES.append(f'Initialized from environment: {var} = {value}') from string_utils import to_bool if len(chunks) == 1 and to_bool(value): @@ -217,8 +317,9 @@ def augment_sys_argv_from_environment_variables(): env = '' -def augment_sys_argv_from_loadfile(): - global saved_messages +def _augment_sys_argv_from_loadfile(): + """Internal. Augment with arguments persisted in a saved file.""" + loadfile = None saw_other_args = False grab_next_arg = False @@ -244,7 +345,7 @@ def augment_sys_argv_from_loadfile(): else: msg = f'Reading commandline arguments from {loadfile}.' print(msg, file=sys.stderr) - saved_messages.append(msg) + SAVED_MESSAGES.append(msg) with open(loadfile, 'r') as rf: newargs = rf.readlines() @@ -254,35 +355,37 @@ def augment_sys_argv_from_loadfile(): def parse(entry_module: Optional[str]) -> Dict[str, Any]: """Main program should call this early in main(). Note that the - bootstrap.initialize wrapper takes care of this automatically. + :code:`bootstrap.initialize` wrapper takes care of this automatically. + This should only be called once per program invocation. """ - global config_parse_called - if config_parse_called: + 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. for arg in sys.argv: - if arg == '--help' or arg == '-h': - args._action_groups = reorder_arg_action_groups(entry_module) + if arg in ('--help', '-h'): + if entry_module is not None: + entry_module = os.path.basename(entry_module) + ARGS._action_groups = _reorder_arg_action_groups_before_help(entry_module) # Examine the environment for variables that match known flags. # For a flag called --example_flag the corresponding environment # variable would be called EXAMPLE_FLAG. If found, hackily add # these into sys.argv to be parsed. - augment_sys_argv_from_environment_variables() + _augment_sys_argv_from_environment_variables() # Look for loadfile and read/parse it if present. This also # works by jamming these values onto sys.argv. - augment_sys_argv_from_loadfile() + _augment_sys_argv_from_loadfile() # Parse (possibly augmented, possibly completely overwritten) # commandline args with argparse normally and populate config. - known, unknown = args.parse_known_args() + known, unknown = ARGS.parse_known_args() config.update(vars(known)) # Reconstruct the argv with unrecognized flags for the benefit of @@ -294,27 +397,26 @@ def parse(entry_module: Optional[str]) -> Dict[str, Any]: 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}') + 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:])) + wf.write("\n".join(ORIG_ARGV[1:])) # Also dump the config on stderr if requested. if config['config_dump']: dump_config() - config_parse_called = True + CONFIG_PARSE_CALLED = True return config def has_been_parsed() -> bool: - """Has the global config been parsed yet?""" - global config_parse_called - return config_parse_called + """Returns True iff the global config has already been parsed""" + return CONFIG_PARSE_CALLED def dump_config(): @@ -327,6 +429,6 @@ def dump_config(): def late_logging(): """Log messages saved earlier now that logging has been initialized.""" logger = logging.getLogger(__name__) - global saved_messages - for _ in saved_messages: + logger.debug('Original commandline was: %s', ORIG_ARGV) + for _ in SAVED_MESSAGES: logger.debug(_)