Update app.py

app.py

@@ -12,7 +12,7 @@ def main():
 
     if api_key:
         # Download BOE rates
-        download_boe_rates()
+        boe_rates_df = download_boe_rates()
 
         # Allow user to upload Excel sheet
         uploaded_file = st.file_uploader("Upload Excel file", type=["xlsx", "xls"])
@@ -39,8 +39,15 @@ def main():
                     'amount': amounts
                 })
 
-                # Calculate late interest
-                df_with_interest = calculate_late_interest(df_calculate, late_interest_rate)
+                # If Bank of England rates are available, adjust the late interest calculation
+                if boe_rates_df is not None:
+                    # Get the latest Bank of England base rate
+                    latest_base_rate = boe_rates_df['Bank Rate'].iloc[-1]
+                    # Calculate late interest with adjusted rate
+                    df_with_interest = calculate_late_interest(df_calculate, late_interest_rate, latest_base_rate)
+                else:
+                    # Calculate late interest using the specified late interest rate
+                    df_with_interest = calculate_late_interest(df_calculate, late_interest_rate)
 
                 # Display calculated late interest
                 total_late_interest = df_with_interest['late_interest'].sum()
@@ -77,10 +84,17 @@ def main():
         st.warning("Please enter your OpenAI API key.")
 
 # Function to calculate late interest
-def calculate_late_interest(data, late_interest_rate):
-    # Calculate late days and late interest
-    data['late_days'] = (data['payment_date'] - data['due_date']).dt.days.clip(lower=0)
-    data['late_interest'] = data['late_days'] * data['amount'] * (late_interest_rate / 100)
+def calculate_late_interest(data, late_interest_rate, base_rate=None):
+    # If base_rate is provided, calculate late interest based on it
+    if base_rate is not None:
+        # Calculate late days and late interest using the adjusted late interest rate
+        data['late_days'] = (data['payment_date'] - data['due_date']).dt.days.clip(lower=0)
+        data['late_interest'] = data['late_days'] * data['amount'] * ((late_interest_rate + base_rate) / 100)
+    else:
+        # Calculate late days and late interest using the provided late interest rate
+        data['late_days'] = (data['payment_date'] - data['due_date']).dt.days.clip(lower=0)
+        data['late_interest'] = data['late_days'] * data['amount'] * (late_interest_rate / 100)
+    
     return data
 
 # Function to analyze Excel sheet and extract relevant information
@@ -111,10 +125,13 @@ def download_boe_rates():
             df = pd.read_html(response.text)[0]
             df.to_csv('boe_rates.csv', index=False)
             st.success("Bank of England rates downloaded successfully.")
+            return df
         else:
             st.error("Failed to retrieve data from the Bank of England website.")
+            return None
     except requests.RequestException as e:
         st.error(f"Failed to download rates: {e}")
+        return None
 
 if __name__ == "__main__":
     main()