Fixes and improvements based on Matt's observations

Fixed and improved many things in the script based on the reviews made by @mattsta. The parallelization suggestion is still to be revised, but code for it was still added (commented).

quantize.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python3
+#!/usr/bin/env python3
 
 """Script to execute quantization on a given model."""
 
@@ -13,30 +13,76 @@ def main():
 
     parser = argparse.ArgumentParser(
         prog='Quantization Script',
-        description='This script quantizes a model.'
+        description='This script quantizes a model or many models.'
+    )
+    parser.add_argument(
+        "models", nargs='+', dest='models',
+        choices=('7B', '13B', '30B', '65B'),
+        help='The models to quantize.'
     )
-
-    parser.add_argument("models", nargs='+', dest='models')
     parser.add_argument(
         '-r', '--remove-16', action='store_true', dest='remove_f16',
         help='Remove the f16 model after quantizing it.'
     )
+    parser.add_argument(
+        '-m', '--models-path', dest='models_path',
+        default=os.path.join(os.getcwd(), "models"),
+        help='Specify the directory where the models are located.'
+    )
+    parser.add_argument(
+        '-q', '--quantize-script-path', dest='quantize_script_path',
+        default=os.getcwd(),
+        help='Specify the path to the "quantize" script.'
+    )
+    # TODO: Revise this code
+    # parser.add_argument(
+    #     '-t', '--threads', dest='threads', type='int',
+    #     default=os.cpu_count(),
+    #     help='Specify the number of threads to use to quantize many models at '
+    #     'once. Defaults to os.cpu_count().'
+    # )
 
     args = parser.parse_args()
 
+    if not os.path.isfile(args.quantize_script_path):
+        print(
+            'The "quantize" script was not found in the current location.\n'
+            "If you want to use it from another location, set the "
+            "--quantize-script-path argument from the command line."
+        )
+        sys.exit(1)
+
     for model in args.models:
-
+        f16_model_path = os.path.join(
-        model_path = os.path.join("models", model, "ggml-model-f16.bin")
+            args.models_path, model, "ggml-model-f16.bin"
-
-        for i in os.listdir(model_path):
-            subprocess.run(
-                ["./quantize", i, i.replace("f16", "q4_0"), "2"],
-                shell=True,
-                check=True
         )
 
+        if not os.path.isfile(f16_model_path):
+            print(
+                "The f16 model (ggml-model-f16.bin) was not found in "
+                f"models/{model}. If you want to use it from another location,"
+                " set the --models-path argument from the command line."
+            )
+            sys.exit(1)
+
+        __run_quantize_script(args.quantize_script_path, f16_model_path)
+
         if args.remove_f16:
-                os.remove(i)
+            os.remove(f16_model_path)
+
+
+# This was extracted to a top-level function for parallelization, if
+# implemented. See https://github.com/ggerganov/llama.cpp/pull/222/commits/f8db3d6cd91bf1a1342db9d29e3092bc12dd783c#r1140496406
+def __run_quantize_script(script_path, f16_model_path):
+    """Run the quantize script specifying the path to it and the path to the
+    f16 model to quantize.
+    """
+
+    new_quantized_model_path = f16_model_path.replace("16", "q4_0")
+    subprocess.run(
+        [script_path, f16_model_path, new_quantized_model_path, "2"],
+        shell=True, check=True
+    )
 
 
 if __name__ == "__main__":
@@ -47,13 +93,5 @@ if __name__ == "__main__":
         print("An error ocurred while trying to quantize the models.")
         sys.exit(1)
 
-    except FileNotFoundError as err:
-        print(
-            f'A FileNotFoundError exception was raised while executing the \
-            script:\n{err}\nMake sure you are located in the root of the \
-            repository and that the models are in the "models" directory.'
-        )
-        sys.exit(1)
-
     except KeyboardInterrupt:
         sys.exit(0)