CLI Simplification (#449)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

ultralytics/yolo/cli.py

@@ -1,18 +1,17 @@
 # Ultralytics YOLO 🚀, GPL-3.0 license
 
+import argparse
 import shutil
 from pathlib import Path
 
-import hydra
+from hydra import compose, initialize
 
 from ultralytics import hub, yolo
-from ultralytics.yolo.configs import get_config
-from ultralytics.yolo.utils import DEFAULT_CONFIG, LOGGER, colorstr
+from ultralytics.yolo.utils import DEFAULT_CONFIG, HELP_MSG, LOGGER, PREFIX, print_settings, yaml_load
 
 DIR = Path(__file__).parent
 
 
-@hydra.main(version_base=None, config_path=str(DEFAULT_CONFIG.parent.relative_to(DIR)), config_name=DEFAULT_CONFIG.name)
 def cli(cfg):
     """
     Run a specified task and mode with the given configuration.
@@ -21,21 +20,13 @@ def cli(cfg):
         cfg (DictConfig): Configuration for the task and mode.
     """
     # LOGGER.info(f"{colorstr(f'Ultralytics YOLO v{ultralytics.__version__}')}")
+    from ultralytics.yolo.configs import get_config
+
     if cfg.cfg:
-        LOGGER.info(f"Overriding default config with {cfg.cfg}")
+        LOGGER.info(f"{PREFIX}Overriding default config with {cfg.cfg}")
         cfg = get_config(cfg.cfg)
     task, mode = cfg.task.lower(), cfg.mode.lower()
 
-    # Special case for initializing the configuration
-    if task == "init":
-        shutil.copy2(DEFAULT_CONFIG, Path.cwd())
-        LOGGER.info(f"""
-        {colorstr("YOLO:")} configuration saved to {Path.cwd() / DEFAULT_CONFIG.name}.
-        To run experiments using custom configuration:
-        yolo cfg=config_file.yaml
-                    """)
-        return
-
     # Mapping from task to module
     task_module_map = {"detect": yolo.v8.detect, "segment": yolo.v8.segment, "classify": yolo.v8.classify}
     module = task_module_map.get(task)
@@ -47,10 +38,66 @@ def cli(cfg):
         "train": module.train,
         "val": module.val,
         "predict": module.predict,
-        "export": yolo.engine.exporter.export,
-        "checks": hub.checks}
+        "export": yolo.engine.exporter.export}
     func = mode_func_map.get(mode)
     if not func:
         raise SyntaxError(f"mode not recognized. Choices are {', '.join(mode_func_map.keys())}")
 
     func(cfg)
+
+
+def entrypoint():
+    """
+    This function is the ultralytics package entrypoint, it's responsible for parsing the command line arguments passed
+    to the package. It's a combination of argparse and hydra.
+
+    This function allows for:
+    - passing mandatory YOLO args as a list of strings
+    - specifying the task to be performed, either 'detect', 'segment' or 'classify'
+    - specifying the mode, either 'train', 'val', 'test', or 'predict'
+    - running special modes like 'checks'
+    - passing overrides to the package's configuration
+
+    It uses the package's default config and initializes it using the passed overrides.
+    Then it calls the CLI function with the composed config
+    """
+    parser = argparse.ArgumentParser(description='YOLO parser')
+    parser.add_argument('args', type=str, nargs='+', help='YOLO args')
+    args = parser.parse_args().args
+
+    tasks = 'detect', 'segment', 'classify'
+    modes = 'train', 'val', 'predict', 'export'
+    special_modes = {
+        'checks': hub.checks,
+        'help': lambda: LOGGER.info(HELP_MSG),
+        'settings': print_settings,
+        'copy-config': copy_default_config}
+
+    overrides = []  # basic overrides, i.e. imgsz=320
+    defaults = yaml_load(DEFAULT_CONFIG)
+    for a in args:
+        if '=' in a:
+            overrides.append(a)
+        elif a in tasks:
+            overrides.append(f'task={a}')
+        elif a in modes:
+            overrides.append(f'mode={a}')
+        elif a in special_modes:
+            special_modes[a]()
+            return
+        elif a in defaults and defaults[a] is False:
+            overrides.append(f'{a}=True')  # auto-True for default False args, i.e. yolo show
+        else:
+            raise (SyntaxError(f"'{a}' is not a valid yolo argument\n{HELP_MSG}"))
+
+    with initialize(version_base=None, config_path=str(DEFAULT_CONFIG.parent.relative_to(DIR)), job_name="YOLO"):
+        cfg = compose(config_name=DEFAULT_CONFIG.name, overrides=overrides)
+        cli(cfg)
+
+
+# Special modes --------------------------------------------------------------------------------------------------------
+def copy_default_config():
+    new_file = Path.cwd() / DEFAULT_CONFIG.name.replace('.yaml', '_copy.yaml')
+    shutil.copy2(DEFAULT_CONFIG, new_file)
+    LOGGER.info(f"{PREFIX}{DEFAULT_CONFIG} copied to {new_file}\n"
+                f"Usage for running YOLO with this new custom config:\nyolo cfg={new_file} args...")