Building a Bitcoin parser in Python

I want to learn more about the technology behind Bitcoin, so what better way to do so than by making a project?

Here is a Bitcoin parser written in Python that I made. It was a very nice learning experience.

The code is in my Github

Installation

python setup.py install

Usage

To deserialize the genesis block:

from bitcaviar_plus.block import deserialize_block


def parse_genesis_block():
    with open('path/to/file/blk00000.dat', 'rb') as f:
        block = deserialize_block(f)
        print(block)

To deserialize the entire blockchain:

import os
from bitcaviar_plus.block import deserialize_block
from bitcaviar_plus.errors import InvalidMagicBytes


def parse_entire_blockchain():
    file_counter = -1
    while True:
        file_counter += 1
        file_name = 'path/to/file/blk{}.dat'.format(str(file_counter).zfill(5))
        with open(file_name, 'rb') as f:
            file_size = os.path.getsize(file_name)
            while f.tell() < file_size:
                try:
                    block = deserialize_block(f)
                except InvalidMagicBytes as e:
                    print(e)

This is the output:

{
    "magic_number": "f9beb4d9",
    "size": "0000011d",
    "id": "000000000019d6...",
    "transaction_count": "01",
    "header": {
        "version": "00000001",
        "previous_block_id": "00000000000000...",
        "merkle_root": "4a5e1e4baab89f3a32...",
        "time": "495fab29",
        "bits": "1d00ffff",
        "nonce": "7c2bac1d"
    },
    "transactions": [
        {
            "version": "00000001",
            "input_count": "01",
            "output_count": "01",
            "lock_time": "00000000",
            "id": "4a5e1e4baab89f3a32518a8...",
            "inputs": [
                {
                    "id": "0000000000000000000000...",
                    "vout": "ffffffff",
                    "script_sig_size": "4d",
                    "script_sig": "04ffff001d01044554686520546...",
                    "sequence": "ffffffff"
                }
            ],
            "outputs": [
                {
                    "value": "000000012a05f200",
                    "script_pub_key_size": "43",
                    "script_pub_key": "4104678afdb0fe55482719..."
                }
            ]
        }
    ]
}

Attribution

Here are some websites that I used to study how Bitcoin works.

Tags: