Blockchain use cases beyond crypto - Mini Project: Build & Apply

Explore Blockchain Use Cases Beyond Crypto

📖 Scenario: You are working as a developer for a company that wants to explore how blockchain technology can be used beyond cryptocurrencies. Your task is to create a simple Python program that lists some real-world blockchain use cases and filters them based on a category.

🎯 Goal: Build a Python program that stores a dictionary of blockchain use cases with their categories, sets a category filter, selects use cases matching that category using dictionary comprehension, and prints the filtered results.

📋 What You'll Learn

Create a dictionary called use_cases with exact entries of blockchain use cases and their categories

Create a variable called filter_category with the exact string value to filter use cases

Use dictionary comprehension with use_cases.items() to create a filtered dictionary called filtered_use_cases containing only use cases matching filter_category

Print the filtered_use_cases dictionary

💡 Why This Matters

🌍 Real World

Blockchain technology is used in many fields beyond cryptocurrencies, such as securing digital identities, improving supply chains, and managing healthcare records. This project helps understand how to organize and filter such information programmatically.

💼 Career

Understanding how to handle and filter data related to blockchain use cases is useful for roles in blockchain development, data analysis, and technology consulting.

1

DATA SETUP: Create the blockchain use cases dictionary

Create a dictionary called use_cases with these exact entries: 'Supply Chain': 'Logistics', 'Digital Identity': 'Security', 'Healthcare Records': 'Health', 'Voting Systems': 'Governance', 'Real Estate': 'Property'

Blockchain / Solidity

# Create the use_cases dictionary with the given entries
# Your code here

Hint

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

2

CONFIGURATION: Set the category filter

Create a variable called filter_category and set it to the string 'Security'

Blockchain / Solidity

use_cases = {
    'Supply Chain': 'Logistics',
    'Digital Identity': 'Security',
    'Healthcare Records': 'Health',
    'Voting Systems': 'Governance',
    'Real Estate': 'Property'
}
# Set the filter_category variable to 'Security'
# Your code here

Hint

Assign the string 'Security' to the variable filter_category.

3

CORE LOGIC: Filter use cases by category using dictionary comprehension

Use dictionary comprehension with use_cases.items() to create a new dictionary called filtered_use_cases that contains only the entries where the category equals filter_category

Blockchain / Solidity

use_cases = {
    'Supply Chain': 'Logistics',
    'Digital Identity': 'Security',
    'Healthcare Records': 'Health',
    'Voting Systems': 'Governance',
    'Real Estate': 'Property'
}
filter_category = 'Security'
# Create filtered_use_cases dictionary using dictionary comprehension
# Your code here

Hint

Use {key: value for key, value in dictionary.items() if condition} to filter the dictionary.

4

OUTPUT: Print the filtered use cases

Write a print statement to display the filtered_use_cases dictionary

Blockchain / Solidity

use_cases = {
    'Supply Chain': 'Logistics',
    'Digital Identity': 'Security',
    'Healthcare Records': 'Health',
    'Voting Systems': 'Governance',
    'Real Estate': 'Property'
}
filter_category = 'Security'
filtered_use_cases = {use_case: category for use_case, category in use_cases.items() if category == filter_category}
# Print the filtered_use_cases dictionary
# Your code here

Hint

Use print(filtered_use_cases) to show the filtered dictionary.

Practice

1. Which of the following is a common use of blockchain technology beyond cryptocurrency?

easy

A. Creating new digital currencies only

B. Running traditional centralized databases

C. Tracking the origin and movement of goods in supply chains

D. Replacing all internet servers

Solution

1. Step 1: Understand blockchain beyond money

   Blockchain is used to keep safe and clear records, not just for digital money.

2. Step 2: Identify common non-crypto uses

   Tracking goods in supply chains is a popular use case to ensure transparency and trust.

3. Final Answer:

   Tracking the origin and movement of goods in supply chains -> Option C

4. Quick Check:

   Blockchain use beyond crypto = Tracking goods [OK]

Hint: Think of blockchain as a secure record keeper beyond money [OK]

Common Mistakes:

• Thinking blockchain only creates cryptocurrencies
• Confusing blockchain with regular databases
• Assuming blockchain replaces all internet servers

2. Which syntax correctly describes a smart contract in blockchain?

easy

A. contract SmartContract { function run() public {} }

B. smart contract run() {}

C. contract = SmartContract()

D. function smartContract run()

Solution

1. Step 1: Recognize smart contract syntax

   Smart contracts are written like small programs with a contract keyword and functions.

2. Step 2: Check syntax correctness

   contract SmartContract { function run() public {} } uses correct syntax with 'contract' keyword and function declaration.

3. Final Answer:

   contract SmartContract { function run() public {} } -> Option A

4. Quick Check:

   Correct smart contract syntax = contract SmartContract { function run() public {} } [OK]

Hint: Look for 'contract' keyword and function inside braces [OK]

Common Mistakes:

• Missing 'contract' keyword
• Using assignment instead of declaration
• Incorrect function declaration syntax

3. What will be the output of this simplified blockchain smart contract code snippet?

mapping(address => uint) public votes;
function vote() public {
  votes[msg.sender] += 1;
}
vote() called twice by same address.

medium

A. votes[msg.sender] = 1

B. votes[msg.sender] = 2

C. votes[msg.sender] = 0

D. Error: duplicate voting not allowed

Solution

1. Step 1: Understand the vote function

   Each call to vote() increases the caller's vote count by 1 in the votes mapping.

2. Step 2: Calculate votes after two calls

   Calling vote() twice adds 1 twice, so votes[msg.sender] becomes 2.

3. Final Answer:

   votes[msg.sender] = 2 -> Option B

4. Quick Check:

   Two votes increment count to 2 [OK]

Hint: Each call adds 1, so two calls add up to 2 [OK]

Common Mistakes:

• Assuming only one vote allowed
• Thinking votes reset after each call
• Confusing mapping with array

4. Identify the error in this blockchain voting smart contract snippet:

mapping(address => bool) public voted;
function vote() public {
  require(!voted[msg.sender]);
  voted[msg.sender] = true;
  votes += 1;
}

medium

A. votes variable is not declared

B. require statement syntax is wrong

C. voted mapping should be uint not bool

D. Function vote() missing return type

Solution

1. Step 1: Check variable declarations

   The code uses 'votes += 1' but 'votes' is not declared anywhere.

2. Step 2: Verify other parts

   require syntax and voted mapping type are correct; vote() functions in Solidity do not need return type.

3. Final Answer:

   votes variable is not declared -> Option A

4. Quick Check:

   Undeclared variable 'votes' causes error [OK]

Hint: Check if all variables used are declared [OK]

Common Mistakes:

• Assuming require syntax is wrong
• Thinking bool mapping is incorrect
• Expecting return type in void functions

5. You want to build a blockchain system to manage digital rights for music tracks. Which feature is most important to include beyond basic blockchain storage?

hard

A. Anonymous voting for favorite tracks

B. A cryptocurrency token for trading music

C. A centralized database for faster queries

D. Smart contracts to automate royalty payments

Solution

1. Step 1: Understand digital rights management needs

   Managing rights requires automatic, trustworthy payment distribution to artists.

2. Step 2: Identify blockchain feature for automation

   Smart contracts can run code to automate royalty payments when music is used or sold.

3. Step 3: Evaluate other options

   Cryptocurrency tokens and voting are unrelated; centralized database loses blockchain benefits.

4. Final Answer:

   Smart contracts to automate royalty payments -> Option D

5. Quick Check:

   Automate payments with smart contracts [OK]

Hint: Use smart contracts to automate rules and payments [OK]

Common Mistakes:

• Choosing cryptocurrency token instead of automation
• Using centralized database losing blockchain trust
• Confusing voting with rights management