Consensus mechanisms overview in Blockchain / Solidity - Mini Project: Build & Apply

Consensus Mechanisms Overview

📖 Scenario: You are learning about blockchain technology. One important part is how computers agree on the data in the blockchain. This is called a consensus mechanism.Different blockchains use different consensus methods. You will create a simple program to list some common consensus mechanisms and their main features.

🎯 Goal: Build a Python dictionary that stores consensus mechanisms as keys and their descriptions as values. Then filter and display only those mechanisms that use energy-efficient methods.

📋 What You'll Learn

Create a dictionary called consensus_mechanisms with exact keys and values

Create a list called energy_efficient with exact consensus names

Use a dictionary comprehension to select only energy-efficient mechanisms

Print the filtered dictionary exactly as shown

💡 Why This Matters

🌍 Real World

Blockchain developers and enthusiasts often need to understand and compare different consensus mechanisms to choose the best one for their projects.

💼 Career

Knowledge of consensus mechanisms is important for blockchain engineers, developers, and architects working on secure and efficient distributed systems.

1

Create the consensus mechanisms dictionary

Create a dictionary called consensus_mechanisms with these exact entries:
'Proof of Work': 'Requires solving complex puzzles using high energy',
'Proof of Stake': 'Validators are chosen based on stake, uses less energy',
'Delegated Proof of Stake': 'Stakeholders vote for delegates to validate blocks',
'Practical Byzantine Fault Tolerance': 'Nodes agree through voting, energy efficient',
'Proof of Authority': 'Validators are pre-approved, low energy use'

Blockchain / Solidity

# Create the consensus_mechanisms dictionary with exact entries
# Your code here

Need a hint?

Use curly braces { } to create the dictionary with the exact keys and values.

2

Create the energy-efficient list

Create a list called energy_efficient containing these exact consensus mechanism names:
'Proof of Stake', 'Practical Byzantine Fault Tolerance', 'Proof of Authority'

Blockchain / Solidity

consensus_mechanisms = {
    'Proof of Work': 'Requires solving complex puzzles using high energy',
    'Proof of Stake': 'Validators are chosen based on stake, uses less energy',
    'Delegated Proof of Stake': 'Stakeholders vote for delegates to validate blocks',
    'Practical Byzantine Fault Tolerance': 'Nodes agree through voting, energy efficient',
    'Proof of Authority': 'Validators are pre-approved, low energy use'
}
# Create the energy_efficient list with exact consensus names
# Your code here

Need a hint?

Use square brackets [ ] to create the list with the exact names as strings.

3

Filter energy-efficient consensus mechanisms

Use a dictionary comprehension to create a new dictionary called filtered_mechanisms that includes only the entries from consensus_mechanisms where the key is in the energy_efficient list.

Blockchain / Solidity

consensus_mechanisms = {
    'Proof of Work': 'Requires solving complex puzzles using high energy',
    'Proof of Stake': 'Validators are chosen based on stake, uses less energy',
    'Delegated Proof of Stake': 'Stakeholders vote for delegates to validate blocks',
    'Practical Byzantine Fault Tolerance': 'Nodes agree through voting, energy efficient',
    'Proof of Authority': 'Validators are pre-approved, low energy use'
}
energy_efficient = ['Proof of Stake', 'Practical Byzantine Fault Tolerance', 'Proof of Authority']
# Create filtered_mechanisms using dictionary comprehension
# Your code here

Need a hint?

Use a dictionary comprehension with a for loop and an if condition to filter keys.

4

Print the filtered consensus mechanisms

Print the filtered_mechanisms dictionary exactly as it is.

Blockchain / Solidity

consensus_mechanisms = {
    'Proof of Work': 'Requires solving complex puzzles using high energy',
    'Proof of Stake': 'Validators are chosen based on stake, uses less energy',
    'Delegated Proof of Stake': 'Stakeholders vote for delegates to validate blocks',
    'Practical Byzantine Fault Tolerance': 'Nodes agree through voting, energy efficient',
    'Proof of Authority': 'Validators are pre-approved, low energy use'
}
energy_efficient = ['Proof of Stake', 'Practical Byzantine Fault Tolerance', 'Proof of Authority']
filtered_mechanisms = {key: value for key, value in consensus_mechanisms.items() if key in energy_efficient}
# Print the filtered_mechanisms dictionary
# Your code here

Need a hint?

Use print(filtered_mechanisms) to display the filtered dictionary.