Rollups (Optimistic vs ZK) in Blockchain / Solidity - Hands-On Comparison

Understanding Rollups: Optimistic vs ZK

📖 Scenario: You are learning about blockchain scaling solutions called rollups. Rollups help process many transactions off the main blockchain to make it faster and cheaper. There are two main types: Optimistic Rollups and Zero-Knowledge (ZK) Rollups.In this project, you will create a simple program to compare how many transactions each rollup type can handle and decide which one is better for a given situation.

🎯 Goal: Build a Python program that stores transaction data for Optimistic and ZK rollups, sets a minimum transaction threshold, filters rollups that meet this threshold, and prints the filtered results.

📋 What You'll Learn

Create a dictionary with exact rollup names and their transaction speeds

Add a threshold variable to filter rollups

Use a dictionary comprehension to select rollups meeting the threshold

Print the filtered rollups clearly

💡 Why This Matters

🌍 Real World

Rollups are important in blockchain to speed up transactions and reduce costs. Understanding how to compare their speeds helps developers choose the right solution.

💼 Career

Blockchain developers and engineers often analyze rollup performance to optimize decentralized applications and improve user experience.

1

Create the rollup transaction speeds dictionary

Create a dictionary called rollup_speeds with these exact entries: 'Optimistic': 200, 'ZK': 1500, 'Other': 100

Blockchain / Solidity

# Create the rollup_speeds dictionary with given values
# Your code here

Need a hint?

Use curly braces {} to create a dictionary with keys and values separated by colons.

2

Set the minimum transaction speed threshold

Create a variable called min_speed and set it to 300 to filter rollups with speeds at least this value

Blockchain / Solidity

rollup_speeds = {'Optimistic': 200, 'ZK': 1500, 'Other': 100}
# Create min_speed variable with value 300
# Your code here

Need a hint?

Just assign the number 300 to the variable min_speed.

3

Filter rollups using dictionary comprehension

Use a dictionary comprehension to create a new dictionary called fast_rollups that includes only rollups from rollup_speeds with speeds greater than or equal to min_speed. Use for name, speed in rollup_speeds.items() in your comprehension.

Blockchain / Solidity

rollup_speeds = {'Optimistic': 200, 'ZK': 1500, 'Other': 100}
min_speed = 300
# Create fast_rollups dictionary with rollups having speed >= min_speed
# Your code here

Need a hint?

Use dictionary comprehension syntax: {key: value for key, value in dict.items() if condition}

4

Print the filtered rollups

Write a print statement to display the fast_rollups dictionary

Blockchain / Solidity

rollup_speeds = {'Optimistic': 200, 'ZK': 1500, 'Other': 100}
min_speed = 300
fast_rollups = {name: speed for name, speed in rollup_speeds.items() if speed >= min_speed}
# Print the fast_rollups dictionary
# Your code here

Need a hint?

Use print(fast_rollups) to show the filtered dictionary.