updated generic.py to_json method to raise ValueError if the column types are not string

Author: chandra-teajunkie

pandas/core/generic.py

@@ -2584,6 +2584,14 @@ def to_json(
             ]
         }}
         """
+
+        if orient == "table":
+            if any(isinstance(col, (int, float)) for col in self.columns):
+                raise ValueError(
+                    "Column names must be strings for JSON serialization with "
+                    "orient='table'."
+                )
+
         from pandas.io import json
 
         if date_format is None and orient == "table":