{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Crime Trend Line Chart\n", "\n", "Shows 5-year crime rate trends across Toronto." ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## 1. Data Reference\n", "\n", "### Source Tables\n", "\n", "| Table | Grain | Key Columns |\n", "|-------|-------|-------------|\n", "| `mart_neighbourhood_safety` | neighbourhood \u00d7 year | year, crime_rate_per_100k, crime_yoy_change_pct |\n", "\n", "### SQL Query" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "import pandas as pd\n", "from sqlalchemy import create_engine\n", "from dotenv import load_dotenv\n", "import os\n", "\n", "# Load .env from project root\n", "load_dotenv('../../.env')\n", "\n", "engine = create_engine(os.environ.get('DATABASE_URL'))\n", "\n", "query = \"\"\"\n", "SELECT\n", " year,\n", " AVG(crime_rate_per_100k) as avg_crime_rate,\n", " AVG(assault_rate_per_100k) as avg_assault_rate,\n", " AVG(auto_theft_rate_per_100k) as avg_auto_theft_rate,\n", " AVG(break_enter_rate_per_100k) as avg_break_enter_rate,\n", " SUM(total_incidents) as total_city_incidents,\n", " AVG(crime_yoy_change_pct) as avg_yoy_change\n", "FROM public_marts.mart_neighbourhood_safety\n", "WHERE year >= (SELECT MAX(year) - 5 FROM public_marts.mart_neighbourhood_safety)\n", "GROUP BY year\n", "ORDER BY year\n", "\"\"\"\n", "\n", "df = pd.read_sql(query, engine)\n", "print(f\"Loaded {len(df)} years of crime data\")" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Transformation Steps\n", "\n", "1. Aggregate by year (city-wide)\n", "2. Convert year to datetime\n", "3. Melt for multi-line by crime type" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "df['date'] = pd.to_datetime(df['year'].astype(str) + '-01-01')\n", "\n", "# Melt for multi-line\n", "df_melted = df.melt(\n", " id_vars=['year', 'date'],\n", " value_vars=['avg_assault_rate', 'avg_auto_theft_rate', 'avg_break_enter_rate'],\n", " var_name='crime_type',\n", " value_name='rate_per_100k'\n", ")\n", "\n", "df_melted['crime_type'] = df_melted['crime_type'].map({\n", " 'avg_assault_rate': 'Assault',\n", " 'avg_auto_theft_rate': 'Auto Theft',\n", " 'avg_break_enter_rate': 'Break & Enter'\n", "})" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Sample Output" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "df[['year', 'avg_crime_rate', 'total_city_incidents', 'avg_yoy_change']]" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## 2. Data Visualization\n", "\n", "### Figure Factory\n", "\n", "Uses `create_price_time_series` (reused for any numeric trend)." ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "import sys\n", "sys.path.insert(0, '../..')\n", "\n", "from portfolio_app.figures.time_series import create_price_time_series\n", "\n", "data = df_melted.to_dict('records')\n", "\n", "fig = create_price_time_series(\n", " data=data,\n", " date_column='date',\n", " price_column='rate_per_100k',\n", " group_column='crime_type',\n", " title='Toronto Crime Trends by Type (5 Years)',\n", ")\n", "\n", "# Remove dollar sign formatting since this is rate data\n", "fig.update_layout(yaxis_tickprefix='', yaxis_title='Rate per 100K')\n", "\n", "fig.show()" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Overall Trend" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# Total crime rate trend\n", "total_data = df[['date', 'avg_crime_rate']].rename(columns={'avg_crime_rate': 'total_rate'}).to_dict('records')\n", "\n", "fig2 = create_price_time_series(\n", " data=total_data,\n", " date_column='date',\n", " price_column='total_rate',\n", " title='Toronto Overall Crime Rate Trend',\n", ")\n", "fig2.update_layout(yaxis_tickprefix='', yaxis_title='Rate per 100K')\n", "fig2.show()" ] } ], "metadata": { "kernelspec": { "display_name": "Python 3", "language": "python", "name": "python3" }, "language_info": { "name": "python", "version": "3.11.0" } }, "nbformat": 4, "nbformat_minor": 4 }