A Step-by-Step Guide: How to Build a Blockchain Development in Python

Hey fellow coders,

Today, I want to share with you an exciting journey into the world of blockchain development using Python. Blockchain technology has been gaining immense popularity due to its decentralized nature and its applications in various industries. So, if you’re ready to dive in, let’s get started on building our very own blockchain!

Step 1: Setting Up Our Environment

First things first, let’s make sure we have Python installed on our system. You can download and install Python from the official website if you haven’t already.

Next, we’ll need to install some additional packages. We’ll be using Flask, a lightweight web framework, for creating a simple API for interacting with our blockchain. You can install Flask using pip:

pip install Flask

Step 2: Understanding the Basics of Blockchain

Before we start coding, let’s quickly go over the basic concepts of blockchain. At its core, a blockchain is a distributed ledger that records transactions across a network of computers. Each block in the chain contains a list of transactions, a timestamp, and a reference to the previous block, forming a chronological chain of blocks.

Step 3: Coding Our Blockchain

Now, let’s dive into the fun part - coding our blockchain! Below is a simple implementation of a blockchain in Python:

import hashlib
import json
from time import time
from flask import Flask, jsonify, request

class Blockchain:
    def __init__(self):
        self.chain = []
        self.current_transactions = []

        # Create the genesis block
        self.new_block(previous_hash='1', proof=100)

    def new_block(self, proof, previous_hash=None):
        Create a new block in the blockchain
        :param proof: <int> The proof given by the Proof of Work algorithm
        :param previous_hash: (Optional) <str> Hash of previous block
        :return: <dict> New Block

        block = {
            'index': len(self.chain) + 1,
            'timestamp': time(),
            'transactions': self.current_transactions,
            'proof': proof,
            'previous_hash': previous_hash or self.hash(self.chain[-1]),

        # Reset the current list of transactions
        self.current_transactions = []

        return block

    def new_transaction(self, sender, recipient, amount):
        Adds a new transaction to the list of transactions
        :param sender: <str> Address of the Sender
        :param recipient: <str> Address of the Recipient
        :param amount: <int> Amount
        :return: <int> The index of the block that will hold this transaction
            'sender': sender,
            'recipient': recipient,
            'amount': amount,

        return self.last_block['index'] + 1

    def hash(block):
        # Hashes a block
        block_string = json.dumps(block, sort_keys=True).encode()
        return hashlib.sha256(block_string).hexdigest()

    def last_block(self):
        return self.chain[-1]

# Instantiate our Node
app = Flask(__name__)

# Instantiate the Blockchain
blockchain = Blockchain()

@app.route('/mine', methods=['GET'])
def mine():
    return "Mining a new Block"

@app.route('/transactions/new', methods=['POST'])
def new_transaction():
    return "Adding a new Transaction"

@app.route('/chain', methods=['GET'])
def full_chain():
    response = {
        'chain': blockchain.chain,
        'length': len(blockchain.chain),
    return jsonify(response), 200

if __name__ == '__main__':
    app.run(host='', port=5000)

Step 4: Testing Our Blockchain

Now that we have our blockchain code ready, let’s fire up our Flask server and test it out. Run the following command in your terminal:

python your_file_name.py

Replace your_file_name.py with the name of your Python file containing the blockchain code.

Once the server is running, you can interact with your blockchain using cURL commands or tools like Postman.

Congratulations! You’ve just built your very own blockchain development in Python. This is just a basic implementation, and there’s a lot more you can do to enhance and expand upon it. I encourage you to explore further and experiment with different features and functionalities.

Feel free to ask any questions or share your thoughts in the comments below. Happy coding!