Update app.py

app.py

@@ -16,7 +16,7 @@ def convert_ci(by_line_item_file, combined_file, password, max_rows):
         office_file.decrypt(decrypted)
 
     # Load "by line item" data and skip last 3 rows
-    by_line_item_df_raw = pd.read_excel(decrypted, skiprows=10, header=None)
+    by_line_item_df_raw = pd.read_excel(decrypted, skiprows=10, header=None, dtype= {4: str, 23: str})
     by_line_item_df_raw = by_line_item_df_raw.iloc[:-3]  # drop last 3 rows
     by_line_item_df = by_line_item_df_raw.iloc[:, [1, 4, 5, 6, 7, 8, 9, 10, 11, 23]].copy()