📊 Day 2: Bar Chart in Python 

🔍 What is a Bar Chart?

A bar chart is used to compare values across different categories.

Each bar represents:

• A category on one axis

• A numeric value on the other axis

The length or height of the bar shows how big the value is.

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✅ When Should You Use a Bar Chart?

Use a bar chart when:

• Data is categorical

• You want to compare counts, totals, or averages

• Order of categories does not depend on time

Real-world examples:

• Sales by product

• Students in each class

• Votes per candidate

• Marks per subject

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❌ Bar Chart vs Line Chart

Bar Chart	Line Chart
Categorical data	Time-based data
Compares values	Shows trends
Bars do not touch	Points are connected

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📊 Example Dataset

Let’s compare sales of different products:

Product	Sales
Laptop	120
Mobile	200
Tablet	90
Headphones	150

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🧠 Python Code: Bar Chart Using Matplotlib

import matplotlib.pyplot as plt

# Data
products = ['Laptop', 'Mobile', 'Tablet', 'Headphones']
sales = [120, 200, 90, 150]

# Create bar chart
plt.bar(products, sales)

# Labels and title
plt.xlabel('Products')
plt.ylabel('Sales')
plt.title('Product Sales Comparison')

# Display chart
plt.show()

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🧩 Code Explanation (Simple)

• plt.bar() → creates the bar chart

• products → categories on x-axis

• sales → numerical values on y-axis

• xlabel() & ylabel() → axis labels

• title() → chart heading

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📌 Important Points to Remember

✔ Bar charts compare categories
✔ Bars do not touch
✔ Simple and easy to interpret
✔ Widely used in reports and dashboards