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Map display with geo spatial index H3

This recipe enables you to display geographic data on a map with H3

Code snippet​

Display geo data from a table​

app.py
import streamlit as st
import streamlit_hexviz as shv
from databricks import sql
from databricks.sdk.core import Config
from databricks.sdk import WorkspaceClient
import pandas as pd

cfg = Config()
w = WorkspaceClient()

# List available SQL warehouses
warehouses = w.warehouses.list()
warehouse_paths = {wh.name: wh.odbc_params.path for wh in warehouses}

# Connect to SQL warehouse
def get_connection(http_path):
    return sql.connect(
        server_hostname=cfg.host,
        http_path=http_path,
        credentials_provider=lambda: cfg.authenticate,
    )

# Read table
def read_table(table_name, conn):
    with conn.cursor() as cursor:
        cursor.execute(f"SELECT * FROM {table_name}")
        return cursor.fetchall_arrow().to_pandas()

# Get data and display on map
warehouse_name = "your_warehouse_name"
table_name = "samples.accuweather.forecast_daily_calendar_metric"

http_path = warehouse_paths[warehouse_name]
conn = get_connection(http_path)
df = read_table(table_name, conn)

# Display map with latitude/longitude columns
shv.h3_map(df, lat="latitude", lon="longitude")

# Display map in case table contains H3 index
h3_col= 'your_h3_column_name'
shv.h3_choropleth(df, h3_col=h3_col)

Resources​

Permissions​

Your app service principal needs the following permissions:

  • CAN USE on the SQL warehouse (only required if reading data from tables)
  • SELECT on the Unity Catalog table (only required if reading data from tables)

See Unity Catalog privileges and securable objects for more information.

Dependencies​

requirements.txt
streamlit
streamlit-hexviz
databricks-sdk
databricks-sql-connector