🚀 Phase 9: Build a Visual Expense Dashboard (Matplotlib)

This guide will show you exactly how to create a professional expense dashboard from your CSV file. The code block is ready to paste into your dashboard.py.

📁 File Structure

📁 your_project_folder/
├── receipt_reader.py
├── dashboard.py         ← you paste this here
├── receipt.jpg
└── expenses.csv          ← created automatically

🎯 GOAL

Cleaning  █████████████████
Food      █████████
Personal  ████████
Others    ████

✅ What You Need

pip install matplotlib

This command installs the matplotlib library needed to draw the bar chart.

✅ Step-by-Step Dashboard Script

Create a new Python file:

📄 dashboard.py


import csv
from collections import defaultdict
import matplotlib.pyplot as plt

# Step 1: Load categorized data from CSV
category_totals = defaultdict(float)

with open('expenses.csv', 'r') as file:
    reader = csv.DictReader(file)
    for row in reader:
        category = row['Category']
        price = float(row['Price'])
        category_totals[category] += price

# Step 2: Prepare data for chart
categories = list(category_totals.keys())
totals = list(category_totals.values())

# Step 3: Create bar chart
plt.figure(figsize=(10, 6))
bars = plt.bar(categories, totals, color='skyblue')
plt.title('Total Expenses by Category')
plt.xlabel('Category')
plt.ylabel('Total (₦)')
plt.xticks(rotation=30)
plt.grid(axis='y')

# Step 4: Add price labels on bars
for bar in bars:
    yval = bar.get_height()
    plt.text(bar.get_x() + bar.get_width()/2, yval + 5, f"₦{int(yval)}", ha='center', fontsize=9)

# Show the chart
plt.tight_layout()
plt.show()

📊 What This Does

Step	Description
Load CSV	Reads your expense data from `expenses.csv`
Group Data	Adds prices for each category using a dictionary
Plot Chart	Draws a bar chart using `matplotlib`

🧪 How to Run

Make sure receipt_reader.py has already been run
Ensure expenses.csv is in the same folder
Run the script:

python dashboard.py

This runs your Python dashboard script and shows the expense bar chart.