摘要：
__str__ is a special method name, like __init__, that is supposed to return a string representation of an object.For example, here is a str method for... 阅读全文
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The init method is a special method that gets invoked when an object is instantiated. Its full name is __init__ (two underscore characters, followed b... 阅读全文
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Python is an object-oriented programing language, which means that it provides features that support object-oriented programming. It is easy to define... 阅读全文
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Sometimes it is useful for a function to modify the objects it gets as parameters. In that case, the changes are visible to the caller. increment, whi... 阅读全文
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In the next few sections, we’ll write two versions of a function called add_time, which calculates the sum of two Time objects. They demonstrate two k... 阅读全文