Update app.py

app.py

@@ -12,21 +12,23 @@ from plotting import (
 )
 
 def load_data_in_chunks(file_path, selected_columns, start_date=None, end_date=None, chunksize=10000):
-    # Load the entire header
+    # Load the entire header to get multi-level column names
     header = pd.read_csv(file_path, nrows=0, header=[0, 1, 2])
     
-    # Filter the required columns
+    # Filter the required columns including datetime
     columns = [col for col in header.columns if col[2] in selected_columns]
-    columns = [('datetime', '', '')] + columns
     
     chunks = []
-    for chunk in pd.read_csv(file_path, chunksize=chunksize, parse_dates=['datetime'], header=[0, 1, 2]):
-        # Filter the necessary columns
+    for chunk in pd.read_csv(file_path, chunksize=chunksize, header=[0, 1, 2], index_col=0, parse_dates=True):
+        # Assign multi-level columns
         chunk.columns = header.columns
+        
+        # Filter the necessary columns
         chunk = chunk[columns]
         
+        # Apply date range filtering if necessary
         if start_date and end_date:
-            chunk = chunk[(chunk[('datetime', '', '')] >= start_date) & (chunk[('datetime', '', '')] <= end_date)]
+            chunk = chunk[(chunk.index >= start_date) & (chunk.index <= end_date)]
         
         chunks.append(chunk)
     
@@ -60,12 +62,6 @@ heatmap_temperature = pn.widgets.Checkbox(
 # Create a loading spinner
 loading_spinner = pn.indicators.LoadingSpinner(width=50, height=50)
 
-# Panel interactive functions
-@pn.depends(
-    inverter_ids.param.value,
-    plot_power_curves.param.value,
-    plot_temperature_curves.param.value,
-)
 @pn.depends(
     inverter_ids.param.value,
     plot_power_curves.param.value,