📅 Day 32: Gantt Chart in Python

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🔹 What is a Gantt Chart?

A Gantt Chart is a timeline-based chart used to visualize project schedules.

It shows:

• Tasks

• Start & end dates

• Duration

• Overlapping activities

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🔹 When Should You Use It?

Use a Gantt chart when:

• Managing projects

• Planning tasks

• Tracking deadlines

• Showing task dependencies

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🔹 Example Scenario

Project Development Plan:

• Requirement Gathering

• Design Phase

• Development

• Testing

• Deployment

A Gantt chart clearly shows when each task starts and ends.

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🔹 Key Idea Behind It

👉 Y-axis = Tasks
👉 X-axis = Timeline
👉 Horizontal bars = Duration
👉 Overlapping bars show parallel tasks

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🔹 Python Code (Gantt Chart using Plotly)

import plotly.express as px
import pandas as pd

data = pd.DataFrame({
    "Task": ["Requirements", "Design", "Development", "Testing"],
    "Start": ["2026-01-01", "2026-01-05", "2026-01-10", "2026-01-20"], 
 "Finish": ["2026-01-05", "2026-01-10", "2026-01-20", "2026-01-30"]
})

fig = px.timeline(
    data,
    x_start="Start",
    x_end="Finish",
    y="Task",
    title="Project Timeline"
)

fig.update_yaxes(autorange="reversed")
 fig.show()

📌 Install Plotly if needed:

pip install plotly

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🔹 Output Explanation

• Each horizontal bar represents a task

• Bar length = task duration

• Tasks are arranged vertically

• Timeline displayed horizontally

The reversed y-axis keeps the first task at the top.

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🔹 Gantt Chart vs Timeline Chart

Aspect	Gantt Chart	Timeline Chart
Task duration	✅	❌
Overlapping tasks	Clear	Limited
Project management	Excellent	Basic
Business use	Very Common	Moderate

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🔹 Key Takeaways

• Best for project planning

• Shows task overlaps clearly

• Easy to track deadlines

• Essential for managers & teams