Fixing C/1B exportfile issue

app.py

@@ -1156,9 +1156,14 @@ def create_position_export_dict(column_name, csv_file, site_var, type_var, sport
                 elif position_filter == 'SFLEX':
                     filtered_df = csv_file.copy()
                 elif position_filter == 'C/1B':
-                    filtered_df = csv_file[
-                        csv_file['Position'].str.contains(['C', '1B'], na=False, regex=False)
-                    ]
+                    # FanDuel MLB: column is C/1B; pool rows use Position C / 1B and often Roster Position "C/1B".
+                    # pandas str.contains(pat) requires a string — passing a list broke this branch and yielded empty ID maps.
+                    pos_series = csv_file['Position'].astype(str).str.strip()
+                    c1b_mask = pos_series.isin(['C', '1B', 'C/1B'])
+                    if 'Roster Position' in csv_file.columns:
+                        rp = csv_file['Roster Position'].astype(str).str.strip()
+                        c1b_mask = c1b_mask | rp.isin(['C/1B', 'C', '1B'])
+                    filtered_df = csv_file[c1b_mask]
                 else:
                     filtered_df = csv_file[
                         csv_file['Position'].str.contains(position_filter, na=False, regex=False)