擅长:python、mysql、java
<p>请参阅<a href="https://stackoverflow.com/q/1132941/476">this topic</a>,了解有关默认参数求值的讨论</p>
<p><code>def __init__(self, weight = Weight)</code>将只在函数定义时计算一次,而<code>Test.Weight</code>将每次计算一次。所以在这种情况下,你会看到不同的结果:</p>
<pre><code>testing = Test()
Test.Weight = 42
testing2 = Test()
print(testing.weight, testing2.weight)
</code></pre>