擅长:python、mysql、java
<p>默认参数在方法声明时计算一次。然后,该值将用于对该方法的所有调用。在</p>
<p>关于stackoverflow <a href="https://stackoverflow.com/questions/1132941/least-astonishment-in-python-the-mutable-default-argument">exploring the reasons for this design</a>和如何<a href="https://stackoverflow.com/questions/366422/what-is-the-pythonic-way-to-avoid-default-parameters-that-are-empty-lists">best avoid these mutable default arguments</a>还有其他问题。在</p>