Blockchain in Python ^v0.3.0

This project is an implementation of a blockchain in Python, which includes core features such as block creation, transaction processing, and a consensus algorithm. It consists of two modules: one implements the blockchain using Flask to create an API, while the other represents a simpler implementation of the blockchain using classes.

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⚠️ Disclaimer

By using this software, you agree to the full disclaimer terms.

Summary: Software provided "AS IS" without warranty. You assume all risks.

Full legal disclaimer: See DISCLAIMER.md

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Warning! This is a fairly old version that I moved to my historical repository and may continue to develop. So this version is still in development and research phase.

Modules:

1. Flask Blockchain

This module creates a blockchain using Flask, allowing you to interact with it via HTTP requests. Key features include:

• Creating a new block: The /mine method runs the proof-of-work algorithm and creates a new block.
• Creating a new transaction: The /transactions/new method allows you to add new transactions to the blockchain.
• Getting the full chain of blocks: The /chain method returns the current chain of blocks and its length.
• Registering new nodes: The /nodes/register method allows you to add new nodes to the network.
• Consensus algorithm: The /nodes/resolve method checks and resolves conflicts in the chain of blocks.

2. Simple Blockchain Implementation

This module implements the basic structure of a blockchain with the Block and Blockchain classes. The main functions include:

• Creating a genesis block: The create_genesis_block method creates the first block in the chain.
• Adding a new block: The add_block method adds a new block to the chain, setting the correct hash of the previous block.

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• pip install -r requirements.txt

• python blockchain.py

• curl http://localhost:5000/mine

{
  "index": 2,
  "message": "New Block Forged",
  "previous_hash": "5d9d222c768d6c501ae28670a7333e0ae39c14d7884650bf12cf32d3961e2682",
  "proof": 35293,
  "transactions": [
    {
      "amount": 1,
      "recipient": "902a4bd96aa44abcb0d9a097bd78c462",
      "sender": "0"
    }
  ]
}

• curl http://localhost:5000/mine

{
  "index": 3,
  "message": "New Block Forged",
  "previous_hash": "c67d3b156c5c3db264331196bb48efb5e6fa0fcfb31f98cf663e38d69089ffb4",
  "proof": 35089,
  "transactions": [
    {
      "amount": 1,
      "recipient": "902a4bd96aa44abcb0d9a097bd78c462",
      "sender": "0"
    }
  ]
}

• curl http://localhost:5000/chain

{
  "chain": [
    {
      "index": 1,
      "previous_hash": 1,
      "proof": 100,
      "timestamp": 1730220820.929162,
      "transactions": []
    },
    {
      "index": 2,
      "previous_hash": "5d9d222c768d6c501ae28670a7333e0ae39c14d7884650bf12cf32d3961e2682",
      "proof": 35293,
      "timestamp": 1730220836.4981325,
      "transactions": [
        {
          "amount": 1,
          "recipient": "902a4bd96aa44abcb0d9a097bd78c462",
          "sender": "0"
        }
      ]
    },
    {
      "index": 3,
      "previous_hash": "c67d3b156c5c3db264331196bb48efb5e6fa0fcfb31f98cf663e38d69089ffb4",
      "proof": 35089,
      "timestamp": 1730220846.5631032,
      "transactions": [
        {
          "amount": 1,
          "recipient": "902a4bd96aa44abcb0d9a097bd78c462",
          "sender": "0"
        }
      ]
    }
  ],
  "length": 3
}

• curl -X POST -H "Content-Type: application/json" -d '{ "sender": "d4ee26eee15148ee92c6cd394edd974e", "recipient": "someone-other-address", "amount": 5 }' "http://localhost:5000/transactions/new"

{
  "message": "Transaction will be added to Block 4"
}

• python blockchain_base.py

Index: 0
Timestamp: 2024-10-30 00:01:20.180414
Data: Genesis Block
Previous Hash: 0
Hash: 02a478085aca11b94a6ea0b5c2cfe9df56dffbe5153df269f3609faa19fc5641

Index: 1
Timestamp: 2024-10-30 00:01:20.180433
Data: Transaction Data
Previous Hash: 02a478085aca11b94a6ea0b5c2cfe9df56dffbe5153df269f3609faa19fc5641
Hash: 3a7bc11cc8e213468fc25b6708b39e41780d5673ffffb995bbfdaa909d37b73e

Index: 2
Timestamp: 2024-10-30 00:01:20.180441
Data: Another Transaction
Previous Hash: 3a7bc11cc8e213468fc25b6708b39e41780d5673ffffb995bbfdaa909d37b73e
Hash: 477333623f8b9819e23412dfda01aee127d63a2744b32515cc2d0678fcf7fac1

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License

Licensed under BSD 3-Clause License • Copyright (©) 2026, Alexander Suvorov

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