Simplify the help on incorrect positional arg

src/turnkeyml/cli/cli.py

@@ -21,11 +21,6 @@ def error(self, message):
         self.print_help()
         sys.exit(2)
 
-    def print_cache_help(self):
-        print("Error: a cache command is required")
-        self.print_help()
-        sys.exit(2)
-
 
 def print_version(_):
     """
@@ -90,11 +85,11 @@ def main():
     # Parser for the "benchmark" command
     #######################################
 
-    def check_extension(choices, file_name):
+    def check_extension(choices, file_name, error_func):
         _, extension = os.path.splitext(file_name.split("::")[0])
         if extension[1:].lower() not in choices:
-            raise exceptions.ArgError(
-                f"input_files must end with .py, .onnx, or .txt (got '{file_name}')"
+            error_func(
+                f"input_files must end with .py, .onnx, or .txt (got '{file_name}')\n"
             )
         return file_name
 
@@ -109,7 +104,9 @@ def check_extension(choices, file_name):
         "input_files",
         nargs="+",
         help="One or more script (.py), ONNX (.onnx), or input list (.txt) files to be benchmarked",
-        type=lambda file: check_extension(("py", "onnx", "txt"), file),
+        type=lambda file: check_extension(
+            ("py", "onnx", "txt"), file, benchmark_parser.error
+        ),
     )
 
     toolchain_select_group = benchmark_parser.add_argument_group(
@@ -500,26 +497,28 @@ def check_extension(choices, file_name):
     # on a target script. If the user doesn't provide a command,
     # we alter argv to insert the command for them.
 
+    # Special characters that indicate a string is a filename, not a command
+    file_chars = [".", "/", "\\", "*"]
+
     if len(sys.argv) > 1:
         first_arg = sys.argv[1]
         if first_arg not in subparsers.choices.keys() and "-h" not in first_arg:
-            if "." in first_arg:
+            if any(char_to_check in first_arg for char_to_check in file_chars):
+                # User has provided a file as the first positional arg
                 sys.argv.insert(1, "benchmark")
             else:
+                # User has provided a command as the first positional arg
                 # Check how close we are from each of the valid options
+                # NOTE: if we are not close to a valid option, we will let
+                # argparse detect and raise the error
                 valid_options = list(subparsers.choices.keys())
                 close_matches = get_close_matches(first_arg, valid_options)
 
-                error_msg = f"Unexpected positional argument `turnkey {first_arg}`. "
                 if close_matches:
-                    error_msg += f"Did you mean `turnkey {close_matches[0]}`?"
-                else:
-                    error_msg += (
-                        "The first positional argument must either be "
-                        "an input file with the .py or .onnx file extension or "
-                        f"one of the following commands: {valid_options}."
+                    raise exceptions.ArgError(
+                        f"Unexpected command `turnkey {first_arg}`. "
+                        f"Did you mean `turnkey {close_matches[0]}`?"
                     )
-                raise exceptions.ArgError(error_msg)
 
     args = parser.parse_args()
 

test/cli.py

@@ -722,7 +722,7 @@ def test_016_skip_compiled(self):
 
     def test_017_invalid_file_type(self):
         # Ensure that we get an error when running turnkey with invalid input_files
-        with self.assertRaises(exceptions.ArgError):
+        with self.assertRaises(SystemExit):
             testargs = ["turnkey", "gobbledegook"]
             with patch.object(sys, "argv", flatten(testargs)):
                 turnkeycli()