Enhance main.py with interactive map features and data handling improvements

- Added support for displaying an interactive map using Folium and GeoPandas.
- Refactored region and municipality retrieval functions for clarity and consistency.
- Introduced a new function to load geospatial data from a file.
- Updated the UI to include tabs for displaying data in table and map formats.
- Enhanced error handling to provide user feedback in case of exceptions.
- Updated dependencies in pyproject.toml to include GeoPandas and Streamlit-Folium.

Author: Adriano Sanges

__pycache__/maptab.cpython-311.pyc

@@ -2,68 +2,109 @@
 
 import duckdb
 import streamlit as st
+import geopandas as gpd
+import folium
+import streamlit_folium as st_folium
+import os
+
+# Set page configuration as the first Streamlit command
+st.set_page_config(layout="wide", page_title="Interactive Real Estate Map", page_icon="🌍")
+
 from init_db import init_db
+from maptab import map_tab
+
+
 
 @st.cache_data(hash_funcs={duckdb.DuckDBPyConnection: id})
-def get_regioni(conn):
-    return conn.execute("SELECT DISTINCT Regione FROM luoghi order by Regione").df()
+def get_regions(conn):
+    return conn.execute("SELECT DISTINCT Regione FROM luoghi ORDER BY Regione").df()
 
 @st.cache_data(hash_funcs={duckdb.DuckDBPyConnection: id})
-def get_comuni(conn, regione):
-    return conn.execute(f"SELECT DISTINCT Comune_descrizione FROM luoghi WHERE Regione = '{regione}' order by Comune_descrizione").df()
+def get_municipalities(conn, region):
+    return conn.execute(f"SELECT DISTINCT Comune_descrizione FROM luoghi WHERE Regione = '{region}' ORDER BY Comune_descrizione").df()
+
+@st.cache_data
+def load_geodataframe(file_path):
+    return gpd.read_file(file_path)
 
+def create_map(data_gdf, highlight_column):
+    m = folium.Map(location=[42.5, 12.5], zoom_start=6, tiles="cartodbpositron")
+
+    for _, row in data_gdf.iterrows():
+        feature = folium.GeoJson(
+            row["geometry"],
+            name=row[highlight_column],
+            tooltip=row[highlight_column],
+            style_function=lambda x: {
+                "fillColor": "blue",
+                "color": "black",
+                "weight": 1,
+                "fillOpacity": 0.4,
+            },
+            highlight_function=lambda x: {"weight": 3, "fillOpacity": 0.7},
+            popup=folium.Popup(f"<b>{row[highlight_column]}</b>", parse_html=True)
+        )
+        feature.add_to(m)
+
+    return m
 
 def main():
     """
     Main function that serves as the entry point for the application.
     """
     try:
-        conn = duckdb.connect(database = "dati-immobiliari.duckdb")
+        conn = duckdb.connect(database="dati-immobiliari.duckdb")
         init_db(conn)
-        
-        st.set_page_config(layout="wide")
-        
-        st.title("Dati immobiliari Agenzia delle Entrate")
-        st.caption("Dati del 2024")
-
-        
-        show_all_columns = st.checkbox("Mostra tutte le colonne", value=False)
-
-        default_columns = {
-            "Comune_descrizione" : "Comune",
-            "Descr_Tipologia" : "Tipologia",
-            "Zona_Descr" : "Zona",
-            "Compr_min" : "Prezzo acquisto minimo al mq (€)",
-            "Compr_max" : "Prezzo acquisto massimo al mq (€)",
-            "Loc_min" : "Prezzo locazione minimo al mq (€)",
-            "Loc_max" : "Prezzo locazione massimo al mq (€)"
-        }
-
-        regioni_dataset = get_regioni(conn)["Regione"]
-        selected_regione =st.selectbox("Seleziona la regione", regioni_dataset)
-
-        if(selected_regione != None):
-            comuni_dataset = get_comuni(conn, selected_regione)["Comune_descrizione"]
-            selected_comune = st.selectbox("Seleziona il comune", comuni_dataset)
-
-            if(selected_comune != None):
-
-                selected_tipologia = st.selectbox("Seleziona la tipologia", ("Abitazioni civili", "Uffici", "Negozi"))
-
-                if(selected_tipologia != None):
-                    result = conn.execute(f"SELECT * FROM joined_data WHERE Regione = '{selected_regione}' and Comune_descrizione = '{selected_comune}' and Descr_Tipologia = '{selected_tipologia}'").df()
-                    readable_columns = {**default_columns, **{col: col for col in result.columns if col not in default_columns}}
-
-                    if(show_all_columns):
-                        st.dataframe(result)
-                        
-                    else:
-                        
-                        display_df = result[list(default_columns.keys())].rename(columns=default_columns)
-                        st.dataframe(display_df)
-                    
+
+        tableTab, mapTab  = st.tabs(["Table", "Map"])
+
+        with tableTab:
+            st.title("Italian Real Estate Prices")
+            st.caption("Downloaded from Agenzia delle Entrate - current data is from 1st semester 2024")
+
+            show_all_columns = st.checkbox("Show all columns", value=False)
+
+            default_columns = {
+                "Comune_descrizione": "Municipality",
+                "Descr_Tipologia": "Type",
+                "Zona_Descr": "Zones",
+                "Compr_min": "Minimum purchase price per sqm (€)",
+                "Compr_max": "Maximum purchase price per sqm (€)",
+                "Loc_min": "Minimum rental price per sqm (€)",
+                "Loc_max": "Maximum rental price per sqm (€)"
+            }
+
+            regions_dataset = get_regions(conn)["Regione"]
+            selected_region = st.selectbox("Select a region", regions_dataset)
+
+            if selected_region is not None:
+                municipalities_dataset = get_municipalities(conn, selected_region)["Comune_descrizione"]
+                selected_municipality = st.selectbox("Select a municipality", municipalities_dataset)
+
+                if selected_municipality is not None:
+                    selected_building_type = st.selectbox("Select the type of building", ("Residential buildings", "Offices", "Shops"))
+
+                    building_types = {
+                        "Residential buildings": "Abitazioni civili",
+                        "Offices": "Uffici",
+                        "Shops": "Negozi"
+                    }
+
+                    if selected_building_type is not None:
+                        result = conn.execute(f"SELECT * FROM joined_data WHERE Regione = '{selected_region}' and Comune_descrizione = '{selected_municipality}' and Descr_Tipologia = '{building_types[selected_building_type]}'").df()
+                        readable_columns = {**default_columns, **{col: col for col in result.columns if col not in default_columns}}
+
+                        if show_all_columns:
+                            st.dataframe(result)
+                        else:
+                            display_df = result[list(default_columns.keys())].rename(columns=default_columns)
+                            st.dataframe(display_df)
+
+        with mapTab:
+            pass
+
     except Exception as e:
-        print(f"An error occurred: {e}")
+        st.error(f"An error occurred: {e}")
         return 1
 
     return 0

data/geojsons/limits_IT_municipalities.geojson

@@ -0,0 +1,108 @@
+#!/usr/bin/env python3
+import os
+import streamlit as st
+import json
+import streamlit_folium as st_folium
+import folium
+import geopandas as gpd
+
+@st.cache_data
+def load_geodataframe(file_path):
+    return gpd.read_file(file_path)
+
+dirname = os.path.dirname(os.path.abspath(__file__))
+regions_filename = os.path.join(dirname, 'data', 'geojsons', 'limits_IT_regions.geojson')
+provinces_filename = os.path.join(dirname, 'data', 'geojsons', 'limits_IT_provinces.geojson')
+municipalities_filename = os.path.join(dirname, 'data', 'geojsons', 'limits_IT_municipalities.geojson')
+
+def create_map(data_gdf, highlight_column, callback_column, callback_key):
+    m = folium.Map(location=[42.5, 12.5], zoom_start=6, tiles="cartodbpositron")
+
+    for _, row in data_gdf.iterrows():
+        feature = folium.GeoJson(
+            row["geometry"],
+            name=row[highlight_column],
+            tooltip=row[highlight_column],
+            style_function=lambda x: {
+                "fillColor": "blue",
+                "color": "black",
+                "weight": 1,
+                "fillOpacity": 0.4,
+            },
+            highlight_function=lambda x: {"weight": 3, "fillOpacity": 0.7},
+            popup=folium.Popup(f"<b>{row[highlight_column]}</b>", parse_html=True)
+        )
+        feature.add_to(m)
+
+        # Optionally, add a marker at the center of the geometry
+        folium.Marker(
+            location=[row["geometry"].centroid.y, row["geometry"].centroid.x],
+            popup=f"<b>{row[highlight_column]}</b>"
+        ).add_to(m)
+
+    return m
+
+def map_tab(conn):
+    st.title("Italian Real Estate Prices")
+    st.caption("Downloaded from Agenzia delle Entrate - current data is from 1st semester 2024")
+
+    if "level" not in st.session_state:
+        st.session_state.level = "region"
+    if "selected_region" not in st.session_state:
+        st.session_state.selected_region = None
+    if "selected_province" not in st.session_state:
+        st.session_state.selected_province = None
+
+    regions_gdf = load_geodataframe(regions_filename)
+    provinces_gdf = load_geodataframe(provinces_filename)
+    municipalities_gdf = load_geodataframe(municipalities_filename)    
+
+    if st.session_state.level == "region":
+        st.write("### Select a Region")
+        m = create_map(regions_gdf, "reg_name", "reg_istat_code", "selected_region")
+        output = st_folium.folium_static(m, height=600)
+
+        # Debugging: Check the entire output structure
+        st.write("Map Output:", output)
+
+        # Check if the map interaction has updated the session state
+        if output and "last_clicked" in output:
+            clicked_properties = output["last_clicked"].get("properties", {})
+            st.write("Clicked Properties:", clicked_properties)  # Debugging: Check clicked properties
+
+            if "reg_istat_code" in clicked_properties:
+                st.session_state.selected_region = clicked_properties["reg_istat_code"]
+                st.session_state.level = "province"
+                st.write(f"Transitioning to province level with region: {st.session_state.selected_region}")
+            else:
+                st.write("No region code found in clicked properties.")
+
+    elif st.session_state.level == "province":
+        st.write(f"### Selected Region: {st.session_state.selected_region}")
+        selected_provinces = provinces_gdf[
+            provinces_gdf["reg_istat_code"] == st.session_state.selected_region
+        ]
+        m = create_map(selected_provinces, "prov_name", "prov_istat_code", "selected_province")
+        st_folium.folium_static(m, height=600)
+
+        # Debugging: Check if a province is selected
+        st.write(f"Selected Province: {st.session_state.selected_province}")
+
+        if st.session_state.selected_province:
+            st.session_state.level = "municipality"
+            st.session_state.selected_province = st.session_state.selected_province
+
+    elif st.session_state.level == "municipality":
+        st.write(f"### Selected Province: {st.session_state.selected_province}")
+        selected_municipalities = municipalities_gdf[
+            municipalities_gdf["prov_istat_code"] == st.session_state.selected_province
+        ]
+        m = create_map(
+            selected_municipalities, "name", "op_id", None
+        )
+        st_folium.folium_static(m, height=600)
+
+    if st.button("Reset"):
+        st.session_state.level = "region"
+        st.session_state.selected_region = None
+        st.session_state.selected_province = None

data/geojsons/limits_IT_provinces.geojson

@@ -6,5 +6,7 @@ readme = "README.md"
 requires-python = ">=3.11"
 dependencies = [
     "duckdb>=1.1.3",
+    "streamlit-folium>=0.23.2",
     "streamlit>=1.40.2",
+    "geopandas>=1.0.1",
 ]