Refactor UI and improve state management

- Refactored the UI to remove tabs and display the chart and data on the main page.
- Improved session state initialization to prevent overwriting widget values on script rerun.
- Added a results count to the sidebar to show the number of data points.
- Simplified chart axis selection by using session state directly.

src/streamlit_app.py

@@ -33,7 +33,7 @@ def load_symbols():
     )
 
 
-# Initialize session state
+# Initialize session state without forcing values onto widgets
 defaults = {
     "date": None,
     "symbols": [],
@@ -46,7 +46,8 @@ defaults = {
     "y_axis": "change_pct",
 }
 for key, value in defaults.items():
-    st.session_state.setdefault(key, value)
+    if key not in st.session_state:
+        st.session_state[key] = value
 
 # Sidebar filters
 with st.sidebar:
@@ -70,6 +71,9 @@ with st.sidebar:
         "Min rel volume", value=st.session_state.min_relvol
     )
 
+    # Placeholder for results count (updated after df load)
+    results_placeholder = st.empty()
+
 # Construct query filters
 f = st.session_state
 filters = []
@@ -91,42 +95,32 @@ if f.min_run:
 # Load data
 df = get_data(filters if filters else None)
 
-# UI
+# Update the sidebar with results count
+with results_placeholder:
+    st.markdown("---")
+    st.markdown(f"**Results: {len(df)}**")
+
+# UI rendering
 if df.empty:
     st.info("No data found with current filters")
 else:
-    tab1, tab2 = st.tabs(["📊 Data", "📈 Chart"])
-
-    with tab1:
-        st.dataframe(df, use_container_width=True)
-
-    with tab2:
-        numeric_cols = df.select_dtypes("number").columns.tolist()
-
-        col1, col2 = st.columns(2)
-        with col1:
-            x_axis = st.selectbox(
-                "X-axis",
-                numeric_cols,
-                index=(
-                    numeric_cols.index(f.get("x_axis", "open"))
-                    if f.get("x_axis", "open") in numeric_cols
-                    else 0
-                ),
-                key="x_axis",
-            )
-        with col2:
-            y_axis = st.selectbox(
-                "Y-axis",
-                numeric_cols,
-                index=(
-                    numeric_cols.index(f.get("y_axis", "change_pct"))
-                    if f.get("y_axis", "change_pct") in numeric_cols
-                    else 1
-                ),
-                key="y_axis",
-            )
-
-        st.scatter_chart(df, x=x_axis, y=y_axis, color="symbol")
-
-    st.write(f"Results: {len(df)}")
+    numeric_cols = df.select_dtypes("number").columns.tolist()
+
+    col1, col2 = st.columns(2)
+    with col1:
+        st.selectbox(
+            "X-axis",
+            numeric_cols,
+            key="x_axis",
+        )
+    with col2:
+        st.selectbox(
+            "Y-axis",
+            numeric_cols,
+            key="y_axis",  # ✅ No index or value conflicts
+        )
+
+    st.scatter_chart(
+        df, x=st.session_state.x_axis, y=st.session_state.y_axis, color="symbol"
+    )
+    st.dataframe(df, use_container_width=True)