Handle zero sequences

app.py

@@ -55,15 +55,18 @@ for seq in sequences:
 
 
 num_pdb_structures = len(pdb_strings)
-grid_columns = int(num_pdb_structures ** 0.5)
-if grid_columns ** 2 < num_pdb_structures:
-    grid_columns += 1
-grid_columns = min(grid_columns, 12)
-grid_rows = (num_pdb_structures + grid_columns - 1) // grid_columns
-import streamlit as st
+if num_pdb_structures == 0:
+    grid_columns = 1
+    grid_rows = 1
+else:
+    grid_columns = int(num_pdb_structures ** 0.5)
+    if grid_columns ** 2 < num_pdb_structures:
+        grid_columns += 1
+    grid_columns = min(grid_columns, 12)
+    grid_rows = (num_pdb_structures + grid_columns - 1) // grid_columns
 
 # Get the width of the viewer from the sidebar
-viewer_width = st.sidebar.number_input("Viewer Width", 100, 2000, 900)
+viewer_width = int(st.sidebar.number_input("Viewer Width", 100, 2000, 900))
 
 # Calculate the width and height of each grid cell
 grid_cell_width = int(viewer_width / grid_columns)