{"id":14143,"date":"2020-01-26T11:15:02","date_gmt":"2020-01-26T15:15:02","guid":{"rendered":"https:\/\/101blockchains.com\/?p=14143"},"modified":"2023-07-14T03:14:54","modified_gmt":"2023-07-14T07:14:54","slug":"build-a-blockchain-in-python","status":"publish","type":"post","link":"https:\/\/101blockchains.com\/build-a-blockchain-in-python\/","title":{"rendered":"How to Build a Blockchain in Python?"},"content":{"rendered":"

If you want to learn how to build a blockchain<\/a>, then you have come to the right place. Let’s dive deep to learn how you can build a blockchain in python.<\/p>\n

There are tons of articles around blockchain, but not all of them talk about building a blockchain from scratch. As a developer, theories are important, but you also need to create a blockchain to understand the concept behind it completely.<\/p>\n

The core idea behind blockchains is its decentralized nature. You will be fascinated by the fact of how it all works inside. Blockchain might sound simple, but inside there are a lot of protocols and algorithms that make it happen. We are going to use Python to create a blockchain from scratch.<\/p>\n

You can also save the article and bookmark it as, “How to build our blockchain.” Believe me; the article will help you in the long run.<\/p>\n

Build your identity as a certified blockchain expert with 101 Blockchains\u2019\u00a0Blockchain Certifications<\/a>\u00a0designed to provide enhanced career prospects.<\/p><\/blockquote>\n

How To Build A Blockchain<\/h2>\n

The best way to learn anything is to learn by doing. To make sure you are on the same page as me, let\u2019s check out the requirements first. We will also briefly describe blockchain so that we both are on the same page.<\/p>\n

\"How <\/picture><\/a><\/p>\n

Please include attribution to 101blockchains.com with this graphic. <a href='https:\/\/101blockchains.com\/blockchain-infographics\/'> <img src='https:\/\/101blockchains.com\/wp-content\/uploads\/2020\/01\/How-to-Build-A-Blockchain-In-Python.png' alt='How to Build A Blockchain In Python='0' \/> <\/a>\r\n<\/pre>\n
Requirement<\/h3>\n
The basic requirement to follow the guide is to know how to code. If you have never coded in your life, then this guide is not for you. I recommend checking out the various beginner-level courses that are available online. I recommend EdX, Udacity, and Coursera for the best learning experience.<\/p>\n
You already a coder? Then, you should know about basic Python. Also, it will help you to follow the \u201cHow To Build A Blockchain\u201d tutorial.<\/p>\n
We created the tutorial so anyone can follow. So, if you do not know and want to learn how to build a blockchain from scratch, you are welcome to do so!<\/p>\n
\u00a0If you do not know Python, do not worry as it is easy to pick up. Check out the Python documentation<\/a> to get started.<\/p>\n
We are going to use Python 3.6+ for the tutorial. If you decide to use other versions of Python, then you might have to do more research for the code to work. For tutorial purposes, I recommend installing the version that I am using.<\/p>\n
Lastly, you should also know about HTTP — the protocol that is used to communicate between two parties on the internet.<\/p>\n
Installing Python using pip<\/p>\n
You need to install Python using pip. You also need to install wonderful Requests and Flask library. To do so, simply run the command below.<\/p>\n
$pip install Flask==0.12.2 requests==2.18.4<\/pre>\n
If you are using the Windows environment, you can directly go to python.org to download the latest version of Python.<\/p>\n
As for me, I downloaded the Python 3.8.1 — the latest build at the time of writing the tutorial.<\/p>\n
For the IDE, I prefer using PyCharm. I am using the Python Community edition for the tutorial. You are free to use any IDE of your choice. Another great alternative is Visual Studio Code — a free, open-source integrated development environment.<\/p>\n
The last tool that you are going to need is Postman — an HTTP client. Alternatively, you can also use cURL.<\/p>\n
I also recommend installing a virtual environment to create a completely different environment for your development. You can follow this guide<\/a> to set it up properly.<\/p>\n
\"certified <\/picture><\/a><\/p>\n
Blockchain Revisited<\/h3>\n
Before we go and build the blockchain, we need to refresh our idea of blockchain. This will help us to stay on the same page.<\/p>\n
Blockchain is a distributed ledger technology<\/a> where peers can participate, interact, and execute transactions without the need for a centralized entity. Each peer has a copy of the ledger, which makes it impossible for hackers to do fraud in the system. The key features of blockchain<\/a> include transparency, immutability, and security. It utilizes advanced cryptocurrency<\/a> algorithms to ensure data security. Also, to reach consensus, a blockchain network will utilize consensus algorithms<\/a> such as Proof-of-Work<\/a>, Proof-of-Stake<\/a>, and so on.<\/p>\n
Start your blockchain journey Now with the\u00a0Enterprise Blockchains Fundamentals<\/a><\/p><\/blockquote>\n
Getting Started With Building a Blockchain<\/h3>\n
With all the prerequisite installations done, we are now ready to get started with our tutorial, \u201cHow to Build A Blockchain.\u201d<\/p>\n
To get started, you need to create a blockchain.py file.<\/p>\n
1. Blockchain Creation<\/h4>\n
The first step is to make a functional blockchain solution. At first, we need to create a Blockchain class. There we will create a constructor that will initiate the chain and transaction list. The chain list will store our blockchain, whereas the transactions will be stored in the current_transacations array.<\/p>\n
def __init__(self):\r\n\r\n\u00a0\u00a0\u00a0self.chain = []\r\n\r\n\u00a0\u00a0\u00a0self.current_transactions = []<\/pre>\n
Next, we need to create a new_block function which will be used to create new blocks and then add them to the existing chain. The code for the new_block function is as below:<\/p>\n
def new_block(self):\r\n\r\n\u00a0\u00a0\u00a0#This function creates new blocks and then adds to the existing chain\r\n\r\n\u00a0\u00a0\u00a0pass<\/pre>\n
The new_transcaction method will create a new transaction and then add the transaction to the already existing transaction list.<\/p>\n
def new_transaction(self):\r\n\r\n\u00a0\u00a0\u00a0#This function adds a new transaction to already existing transactions\r\n\r\n\u00a0\u00a0\u00a0pass<\/pre>\n
We also have a hash function that is used to create the hash for a block.<\/pre>\n
\u00a0@staticmethod\r\n\r\ndef hash(block):\r\n\r\n\u00a0\u00a0\u00a0#Used for hashing a block<\/pre>\n
The last function that we are going to create last_block. It is used to call the last block in the chain.<\/p>\n
We can also create three more functions here.<\/p>\n