fix column_associations when column names are not strings

Author: jeromedockes

skrub/_check_input.py

@@ -20,14 +20,6 @@ def cast_column_names_to_strings(df):
 
 
 def _column_names_to_strings(column_names):
-    non_string = [c for c in column_names if not isinstance(c, str)]
-    if not non_string:
-        return column_names
-    warnings.warn(
-        f"Some dataframe column names are not strings: {non_string}.\n"
-        "All dataframe column names must be strings in skrub pipelines; "
-        "converting to strings."
-    )
     return list(map(str, column_names))
 
 

skrub/_column_associations.py

@@ -134,7 +134,7 @@ def _stack_symmetric_associations(associations, df):
         right_indices[order],
         associations[order],
     )
-    col_names = np.asarray(list(map(str, sbd.column_names(df))))
+    col_names = np.asarray(sbd.column_names(df))
     left_column_names, right_column_names = (
         col_names[left_indices],
         col_names[right_indices],