Actual changes reflected

src/_pytest/mark/structures.py

@@ -162,25 +162,24 @@ class ParameterSet(NamedTuple):
         del argvalues
 
         if parameters:
+
             # Check all parameter sets have the correct number of values.
             for param in parameters:
                 if len(param.values) != len(argnames):
+                    # Construct a string representation of the expected parameter names
+                    expected_argnames = ', '.join(argnames)
+                    # Construct a string representation of the provided parameter values
+                    provided_values = ', '.join(map(repr, param.values))
                     msg = (
-                        '{nodeid}: in "parametrize" the number of names ({names_len}):\n'
-                        "  {names}\n"
-                        "must be equal to the number of values ({values_len}):\n"
-                        "  {values}"
-                    )
-                    fail(
-                        msg.format(
-                            nodeid=nodeid,
-                            values=param.values,
-                            names=argnames,
-                            names_len=len(argnames),
-                            values_len=len(param.values),
-                        ),
-                        pytrace=False,
+                        f'{nodeid}: \n\n Error in parameterization for test "{func.__name__}".\n '
+                        f'The number of specified parameters ({len(argnames)}) '
+                        f'does not match the number of provided values ({len(param.values)}): {provided_values}. \n'
+                        f' Please ensure that the correct number of parameter names '
+                        f'({len(param.values)}) are separated by commas within quotes.\n\n'
+                        f'Require more than parameter names: \"{expected_argnames}\"'
                     )
+
+                    fail(msg, pytrace=False)
         else:
             # Empty parameter set (likely computed at runtime): create a single
             # parameter set with NOTSET values, with the "empty parameter set" mark applied to it.

src/_pytest/python.py

@@ -1371,11 +1371,19 @@ class Metafunc:
 
         # num_ids == 0 is a special case: https://github.com/pytest-dev/pytest/issues/1849
         if num_ids != len(parametersets) and num_ids != 0:
-            msg = "In {}: {} parameter sets specified, with different number of ids: {}"
-            fail(msg.format(func_name, len(parametersets), num_ids), pytrace=False)
+            # Construct a string representation of the expected parameter sets
+            expected_paramsets = len(parametersets)
+
+            msg = (
+                f"In {func_name}: \n\n"
+                f" Specified {expected_paramsets} parameter sets with {num_ids} different ids. \n"
+                f" Ensure all subparameters are correctly grouped within a single set of quotation marks."
+            )
+            fail(msg, pytrace=False)
 
         return list(itertools.islice(ids, num_ids))
 
+   
     def _resolve_args_directness(
         self,
         argnames: Sequence[str],
@@ -1402,8 +1410,24 @@ class Metafunc:
             arg_directness = dict.fromkeys(argnames, "direct")
             for arg in indirect:
                 if arg not in argnames:
+                    # Construct a list of valid parameter names
+                    valid_params = ', '.join([f'"{name}"' for name in argnames])
+                    
+                    # Construct a string representing the expected number of parameters
+                    expected_param_count = len(indirect[0])
+                    
+                    # Construct a string representing the actual number of parameters provided
+                    actual_param_count = len(argnames)
+
+                    
                     fail(
-                        f"In {self.function.__name__}: indirect fixture '{arg}' doesn't exist",
+                        f"In function {self.function.__name__}: {argnames} is not a valid parameter. "
+                        f"Expected {expected_param_count} sub parameters, but only {actual_param_count} were provided. \n\n"
+                        f"Make sure to pass parameter names as strings without quotes, separated by commas, \n "
+                        f"e.g., '@pytest.mark.parametrize({valid_params}, <Input Values>)'"
+                        f"\n\n"
+                        f"Or if multiple parameters are used, separate them by commas. \n "
+                        f"e.g., '@pytest.mark.parametrize(\"arg1, arg2\", <Input Tuples>)'",
                         pytrace=False,
                     )
                 arg_directness[arg] = "indirect"
@@ -1415,6 +1439,9 @@ class Metafunc:
             )
         return arg_directness
 
+
+
+
     def _validate_if_using_arg_names(
         self,
         argnames: Sequence[str],