Address coments from CodeQL and SonarCloud (#799)

Author: mauvilsa

jsonargparse/_optionals.py

@@ -298,7 +298,7 @@ def omegaconf_load(value):
         if isinstance(value_pyyaml, (str, int, float, bool)) or value_pyyaml is None:
             return value_pyyaml
         value_omegaconf = OmegaConf.to_object(OmegaConf.load(io.StringIO(value)))
-        str_ref = {k: None for k in [value]}
+        str_ref = dict.fromkeys([value], None)
         return value_pyyaml if value_omegaconf == str_ref else value_omegaconf
 
     return omegaconf_load

jsonargparse/_type_checking.py

@@ -14,4 +14,4 @@
 
     from ._core import ActionsContainer, ArgumentGroup, ArgumentParser
 else:
-    globals().update({k: None for k in __all__})
+    globals().update(dict.fromkeys(__all__, None))

jsonargparse/typing.py

@@ -6,7 +6,6 @@
 import pathlib
 import re
 import sys
-from re import Pattern
 from typing import Any, Callable, Optional, Union
 
 if sys.version_info >= (3, 10):
@@ -181,7 +180,7 @@ def validation_fn(cls, v):
 
 def restricted_string_type(
     name: str,
-    regex: Union[str, Pattern],
+    regex: Union[str, re.Pattern],
     docstring: Optional[str] = None,
 ) -> _TypeAlias:
     """Creates or returns an already registered restricted string type class.