Python code modernization, 1/n (#1141)

* Remove unicode text prefixes.

* Replace str.format() uses with f-strings.

* Replace % with f-strings, and do some cleanup.

* Fix wrong variable.

* Avoid unnecessary string conversion.

plugins/module_utils/_api/context/api.py

@@ -146,14 +146,14 @@ class ContextAPI(object):
                         names.append(name)
                     except Exception as e:
                         raise errors.ContextException(
-                            "Failed to load metafile {filepath}: {e}".format(filepath=filepath, e=e),
+                            f"Failed to load metafile {filepath}: {e}"
                         ) from e
 
         contexts = [cls.get_default_context()]
         for name in names:
             context = Context.load_context(name)
             if not context:
-                raise errors.ContextException("Context {context} cannot be found".format(context=name))
+                raise errors.ContextException(f"Context {name} cannot be found")
             contexts.append(context)
         return contexts
 
@@ -174,7 +174,7 @@ class ContextAPI(object):
         err = write_context_name_to_docker_config(name)
         if err:
             raise errors.ContextException(
-                'Failed to set current context: {err}'.format(err=err))
+                f'Failed to set current context: {err}')
 
     @classmethod
     def remove_context(cls, name):

plugins/module_utils/_api/context/config.py

@@ -29,7 +29,7 @@ def get_current_context_name_with_source():
     if docker_cfg_path:
         try:
             with open(docker_cfg_path) as f:
-                return json.load(f).get("currentContext", "default"), "configuration file {file}".format(file=docker_cfg_path)
+                return json.load(f).get("currentContext", "default"), f"configuration file {docker_cfg_path}"
         except Exception:
             pass
     return "default", "fallback value"

plugins/module_utils/_api/context/context.py

@@ -62,7 +62,7 @@ class Context(object):
             if not isinstance(v, dict):
                 # unknown format
                 raise ContextException(
-                    "Unknown endpoint format for context {name}: {v}".format(name=name, v=v),
+                    f"Unknown endpoint format for context {name}: {v}",
                 )
 
             self.endpoints[k] = v
@@ -118,7 +118,7 @@ class Context(object):
         except (OSError, KeyError, ValueError) as e:
             # unknown format
             raise Exception(
-                "Detected corrupted meta file for context {name} : {e}".format(name=name, e=e)
+                f"Detected corrupted meta file for context {name} : {e}"
             ) from e
 
         # for docker endpoints, set defaults for
@@ -193,7 +193,7 @@ class Context(object):
             rmtree(self.tls_path)
 
     def __repr__(self):
-        return "<{classname}: '{name}'>".format(classname=self.__class__.__name__, name=self.name)
+        return f"<{self.__class__.__name__}: '{self.name}'>"
 
     def __str__(self):
         return json.dumps(self.__call__(), indent=2)