Python - Serialization - Big- and Little-Endian Redux - little-endian to int, int class, from_bytes method

Programming Bitcoin
Learn How to Program Bitcoin from Scratch
楽天ブックス(Kobo) 紀伊國屋書店(Kinoppy)

開発環境

• macOS Mojave - Apple (OS)
• Emacs (Text Editor)
• Windows 10 Pro (OS)
• Visual Studio Code (Text Editor)
• Python 3.7 (プログラミング言語)

Programming Bitcoin: Learn How to Program Bitcoin from Scratch (Jimmy Song(著)、O'Reilly Media)のChapter 4(Serialization)、Big- and Little-Endian Redux、Exercises 7(86)の解答を求めてみる。

コード

Python 3

#!/usr/bin/env python3
from unittest import TestCase, main


def little_endian_to_int(b: bytes) -> int:
    return int.from_bytes(b, 'little')


class MyTestCase(TestCase):
    def setUp(self):
        pass

    def tearDown(self):
        pass

    def test_little_endian_to_int_1(self):
        self.assertEqual(little_endian_to_int(b'\x01\x00'), 16 ** 0 * 1)

    def test_little_endian_to_int_2(self):
        self.assertEqual(little_endian_to_int(b'\x00\x01'), 16 ** 2 * 1)


if __name__ == '__main__':
    for b in [b'\x10\x00', b'\x00\x10']:
        for o in [b, little_endian_to_int(b)]:
            print(o)
        print()
    main()

入出力結果(cmd(コマンドプロンプト)、Terminal、Jupyter(IPython))

C:\Users\...>py sample7.py -v
b'\x10\x00'
16

b'\x00\x10'
4096

test_little_endian_to_int_1 (__main__.MyTestCase) ... ok
test_little_endian_to_int_2 (__main__.MyTestCase) ... ok

----------------------------------------------------------------------
Ran 2 tests in 0.000s

OK

C:\Users\...>