Car Sales Data Engineering & Analytics
Skill by ara.so — Data Skills collection.
A comprehensive data engineering and analytics framework for processing ~24K car sales records with ETL pipelines, statistical modeling, and interactive Streamlit dashboards. Provides 15 pre-built analyses covering pricing trends, regional patterns, demographic insights, and feature correlations.
Installation
This project uses uv for package management:
Dependencies: Python 3.10+, pandas, numpy, matplotlib, scipy, streamlit
Quick Start
Launch Interactive Dashboard
Run Full Pipeline
This will:
- Load and clean
data/Car sales.csv - Generate
outputs/cleaned_data.csv - Create 15 PNG charts in
outputs/figures/
Core Module: src/analysis.py
The main analysis engine provides ETL, statistics, and modeling capabilities.
Data Loading & Cleaning
Key Columns:
car_id,date,customer_name,dealer_name,company,modelyear,price,body_style,transmission,colordealer_no,dealer_region,phone,gender,annual_income
Statistical Summaries
Generate Individual Analyses
Statistical Modeling
Streamlit Dashboard (src/ui.py)
Page Structure
The dashboard provides 6 interactive sections:
- 📊 Overview - Data summary, sample rows, statistics
- 💰 Sales & Revenue - Price trends, regional analysis
- 👥 Demographics - Gender, income patterns
- 🔧 Product Insights - Brand, body style, transmission
- 📈 Statistical Modeling - Regression, outliers, normality
- 🔍 Filter & Explore - Custom filters with CSV export
- ⚖️ Compare Segments - Side-by-side comparison with t-tests
Custom Filtering Example
Common Analysis Patterns
Price Analysis by Category
Regional & Temporal Analysis
Statistical Tests
Configuration
File Paths
Default paths are defined in src/analysis.py:
Streamlit Configuration
Create .streamlit/config.toml for dashboard customization:
Running Full Pipeline Programmatically
Troubleshooting
Missing Data Issues
Date Parsing Errors
Memory Issues with Large Datasets
Streamlit Port Conflicts
Key Insights Reference
- Total Records: 23,906 sales
- Revenue: $655.6M total
- Pricing: $27,426 avg, $23,000 median
- Top Body Style: SUV (27%)
- Top Region: Austin (17%)
- Premium Brand: Cadillac ($37,557 avg)
- Demographics: 79% Male, 21% Female
- Transmission: 53% Automatic, 47% Manual

