Python - Using Methods - str class, methods(count), doctest module, testmod method

Practical Programming
楽天ブックス 紀伊国屋書店

開発環境

• macOS Catalina - 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)

Practical Programming: An Introduction to Computer Science Using Python 3.6 (Paul Gries(著)、Jennifer Campbell(著)、Jason Montojo(著)、Pragmatic Bookshelf)のChapter 7(Using Methods)、Exercise 12の解答を求めてみる。

コード

Python 3

#!/usr/bin/env python3
import doctest


def total_occurrences(s1: str, s2: str, ch: str) -> int:
    '''
    >>> total_occurrences('color', 'yellow', 'l')
    3
    >>> total_occurrences('red', 'blue', 'l')
    1
    >>> total_occurrences('green', 'purple', 'b')
    0
    '''
    if len(ch) != 1:
        raise ValueError(f'len("{ch}") want 1, got {len(ch)}')
    return s1.count(ch) + s2.count(ch)


if __name__ == '__main__':
    doctest.testmod()

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

% ./sample12.py -v
Trying:
    total_occurrences('color', 'yellow', 'l')
Expecting:
    3
ok
Trying:
    total_occurrences('red', 'blue', 'l')
Expecting:
    1
ok
Trying:
    total_occurrences('green', 'purple', 'b')
Expecting:
    0
ok
1 items had no tests:
    __main__
1 items passed all tests:
   3 tests in __main__.total_occurrences
3 tests in 2 items.
3 passed and 0 failed.
Test passed.
%