Enabled ruff PERF ruleset for performance checking

Also:
- Converted a couple loops to list or dictionary comprehensions for performance
- Added a "make typecheck" command for running mypy by itself

Author: tleonhardt

Makefile

@@ -21,6 +21,10 @@ format: ## Perform ruff formatting
 lint: ## Perform ruff linting
 	@uv run ruff check --fix
 
+.PHONY: typecheck
+typecheck: ## Perform type checking
+	@uv run mypy
+
 .PHONY: test
 test: ## Test the code with pytest.
 	@echo "🚀 Testing code: Running pytest"

cmd2/argparse_custom.py

@@ -812,10 +812,7 @@ def _add_argument_wrapper(
         kwargs['nargs'] = nargs_adjusted
 
     # Extract registered custom keyword arguments
-    custom_attribs: dict[str, Any] = {}
-    for keyword, value in kwargs.items():
-        if keyword in CUSTOM_ACTION_ATTRIBS:
-            custom_attribs[keyword] = value
+    custom_attribs = {keyword: value for keyword, value in kwargs.items() if keyword in CUSTOM_ACTION_ATTRIBS}
     for keyword in custom_attribs:
         del kwargs[keyword]
 

cmd2/parsing.py

@@ -214,8 +214,7 @@ def argv(self) -> list[str]:
         """
         if self.command:
             rtn = [utils.strip_quotes(self.command)]
-            for cur_token in self.arg_list:
-                rtn.append(utils.strip_quotes(cur_token))
+            rtn.extend(utils.strip_quotes(cur_token) for cur_token in self.arg_list)
         else:
             rtn = []
 

pyproject.toml

@@ -190,9 +190,9 @@ select = [
     "ISC", # flake8-implicit-str-concat (warnings related to implicit vs explicit string concatenation)
     "LOG", # flake8-logging (warn about potential logger issues, but very pedantic)
     # "N", # pep8-naming (force idiomatic naming for classes, functions/methods, and variables/arguments)
-    "NPY", # NumPy specific rules
-    "PD",  # pandas-vet (Pandas specific rules)
-    # "PERF", # Perflint (warn about performance issues)
+    "NPY",  # NumPy specific rules
+    "PD",   # pandas-vet (Pandas specific rules)
+    "PERF", # Perflint (warn about performance issues)
     # "PGH", # pygrep-hooks (force specific rule codes when ignoring type or linter issues on a line)
     # "PIE", # flake8-pie (eliminate unnecessary use of pass, range starting at 0, etc.)
     "PLC", # Pylint Conventions