『ロバストPython』10章 ピザ仕様クラスによる不変式の例

例：ピザの半径

assert 6 <= dough_radius_in_inches <= 12, 'Dough must be between 6 and 12 inches'

code:assert_behavior.py

>> dough_radius_in_inches = 7

>> assert 6 <= dough_radius_in_inches <= 12, 'Dough must be between 6 and 12 inches'

>> dough_radius_in_inches = 5

>> assert 6 <= dough_radius_in_inches <= 12, 'Dough must be between 6 and 12 inches'

Traceback (most recent call last):

File "<stdin>", line 1, in <module>

AssertionError: Dough must be between 6 and 12 inches

例：ピザのトッピング

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