Learn Python by Doing: Part 9

Visualization with Python libraries Seaborn and Matplotlib

Python Visualization Libraries — Interview Q&A (Code-First)

PART 1: MATPLOTLIB (FOUNDATION — MUST KNOW)

Matplotlib is low-level, flexible, and base for Seaborn.

1️⃣ What is Matplotlib? When is it preferred?

Answer
Matplotlib is a low-level plotting library used for custom, fine-grained control over plots.

Preferred when:

• Custom layouts
• Subplots & dashboards
• Scientific plots
• ML metric visualization (loss, accuracy)
• Production-grade control

2️⃣ Difference between plt.plot() and plt.scatter()?

import matplotlib.pyplot as plt
x = [1, 2, 3, 4]
y = [10, 20, 25, 30]
plt.plot(x, y) # Line chart
plt.scatter(x, y) # Scatter plot
plt.show()

| Function    | Use                         |
| ----------- | --------------------------- |
| `plot()`    | Trend over sequence         |
| `scatter()` | Relationship / distribution |

3️⃣ How to create subplots?

fig, axes = plt.subplots(1, 2, figsize=(10, 4))…