refactor(ruff): Apply TC006 fixes

altair/utils/core.py

@@ -383,7 +383,7 @@ def to_list_if_array(val):
         # We know that the column names are strings from the isinstance check
         # further above but mypy thinks it is of type Hashable and therefore does not
         # let us assign it to the col_name variable which is already of type str.
-        col_name = cast(str, dtype_item[0])
+        col_name = cast("str", dtype_item[0])
         dtype = dtype_item[1]
         dtype_name = str(dtype)
         if dtype_name == "category":

altair/utils/mimebundle.py

@@ -140,7 +140,7 @@ def spec_to_mimebundle(
     if format in {"png", "svg", "pdf", "vega"}:
         return _spec_to_mimebundle_with_engine(
             spec,
-            cast(Literal["png", "svg", "pdf", "vega"], format),
+            cast("Literal['png', 'svg', 'pdf', 'vega']", format),
             internal_mode,
             engine=engine,
             format_locale=embed_options.get("formatLocale", None),

altair/utils/plugin_registry.py

@@ -134,7 +134,7 @@ def __init__(
                 f"https://docs.astral.sh/ruff/rules/assert/"
             )
             deprecated_warn(msg, version="5.4.0")
-            self.plugin_type = cast(IsPlugin, _is_type(plugin_type))
+            self.plugin_type = cast("IsPlugin", _is_type(plugin_type))
         else:
             self.plugin_type = plugin_type
         self._active: Plugin[R] | None = None
@@ -214,7 +214,7 @@ def _enable(self, name: str, **options) -> None:
                     raise ValueError(self.entrypoint_err_messages[name]) from err
                 else:
                     raise NoSuchEntryPoint(self.entry_point_group, name) from err
-            value = cast(PluginT, ep.load())
+            value = cast("PluginT", ep.load())
             self.register(name, value)
         self._active_name = name
         self._active = self._plugins[name]

altair/vegalite/v5/api.py

@@ -798,7 +798,7 @@ def _parse_when_compose(
     if constraints:
         iters.append(_parse_when_constraints(constraints))
     r = functools.reduce(operator.and_, itertools.chain.from_iterable(iters))
-    return t.cast(_expr_core.BinaryExpression, r)
+    return t.cast("_expr_core.BinaryExpression", r)
 
 
 def _parse_when(
@@ -1107,7 +1107,7 @@ def when(
         conditions = self.to_dict()
         current = conditions["condition"]
         if isinstance(current, list):
-            conditions = t.cast(_Conditional[_Conditions], conditions)
+            conditions = t.cast("_Conditional[_Conditions]", conditions)
             return ChainedWhen(condition, conditions)
         elif isinstance(current, dict):
             cond = _reveal_parsed_shorthand(current)
@@ -1384,7 +1384,7 @@ def param(
             parameter.empty = empty
         elif empty in empty_remap:
             utils.deprecated_warn(warn_msg, version="5.0.0")
-            parameter.empty = empty_remap[t.cast(str, empty)]
+            parameter.empty = empty_remap[t.cast("str", empty)]
         else:
             raise ValueError(warn_msg)
 
@@ -3086,7 +3086,7 @@ def transform_filter(
             verbose_composition = chart.transform_filter((datum.year == 2000) & (datum.sex == 1))
             chart.transform_filter(year=2000, sex=1)
         """
-        if depr_filter := t.cast(Any, constraints.pop("filter", None)):
+        if depr_filter := t.cast("Any", constraints.pop("filter", None)):
             utils.deprecated_warn(
                 "Passing `filter` as a keyword is ambiguous.\n\n"
                 "Use a positional argument for `<5.5.0` behavior.\n"
@@ -3986,7 +3986,7 @@ def from_dict(
                 pass
 
         # As a last resort, try using the Root vegalite object
-        return t.cast(_TSchemaBase, core.Root.from_dict(dct, validate))
+        return t.cast("_TSchemaBase", core.Root.from_dict(dct, validate))
 
     def to_dict(
         self,