updated to_json function with orient=table to raise a ValueError if t…

…he column types are anything other than string

pandas/core/generic.py

@@ -2378,7 +2378,7 @@ def to_json(
                 Describing the data, where data component is like ``orient='records'``.
 
                 Note that If `orient='table'`, column names must be strings.
-                Using numeric column names will raise a `ValueError`.
+                Using non string column names will raise a `ValueError`.
 
         date_format : {{None, 'epoch', 'iso'}}
             Type of date conversion. 'epoch' = epoch milliseconds,
@@ -2450,7 +2450,7 @@ def to_json(
         schema.
 
         When using ``orient='table'``, column names must be strings due to JSON
-        requiring string keys. If column names are numeric (integers or floats),
+        requiring string keys. If column names are anything other than string,
         a `ValueError` will be raised.
 
         Examples
@@ -2594,7 +2594,7 @@ def to_json(
 
         if orient == "table":
             if hasattr(self, "columns") and any(
-                isinstance(col, (int, float)) for col in self.columns
+                not isinstance(col, str) for col in self.columns
             ):
                 raise ValueError(
                     "Column names must be strings for JSON serialization with "