Fix explicit checks

Author: nicoddemus

src/_pytest/config/__init__.py

@@ -1647,10 +1647,6 @@ def _getini(self, name: str):
                 if self.inipath is not None
                 else self.invocation_params.dir
             )
-            if not isinstance(value, (str, Sequence)):
-                raise TypeError(
-                    f"Expected str or sequence for option {name} of type str/list, but got: {value!r}"
-                ) from None
             input_values = shlex.split(value) if isinstance(value, str) else value
             return [dp / x for x in input_values]
         elif type == "args":
@@ -1665,15 +1661,15 @@ def _getini(self, name: str):
         elif type == "string":
             return value
         elif type == "int":
-            if not isinstance(value, (str, int)):
+            if not isinstance(value, str):
                 raise TypeError(
-                    f"Expected str or int for option {name} of type integer, but got: {value!r}"
+                    f"Expected an int string for option {name} of type integer, but got: {value!r}"
                 ) from None
             return int(value)
         elif type == "float":
-            if not isinstance(value, (str, float)):
+            if not isinstance(value, str):
                 raise TypeError(
-                    f"Expected str or float for option {name} of type float, but got: {value!r}"
+                    f"Expected a float string for option {name} of type float, but got: {value!r}"
                 ) from None
             return float(value)
         elif type is None:

testing/test_config.py

@@ -880,7 +880,9 @@ def pytest_addoption(parser):
             """
         )
         config = pytester.parseconfig()
-        with pytest.raises(TypeError, match="Expected str or int for option ini_param"):
+        with pytest.raises(
+            TypeError, match="Expected an int string for option ini_param"
+        ):
             _ = config.getini("ini_param")
 
     @pytest.mark.parametrize("str_val, float_val", [("10.5", 10.5), ("no-ini", 2.2)])
@@ -918,7 +920,7 @@ def pytest_addoption(parser):
         )
         config = pytester.parseconfig()
         with pytest.raises(
-            TypeError, match="Expected str or float for option ini_param"
+            TypeError, match="Expected a float string for option ini_param"
         ):
             _ = config.getini("ini_param")