擅长:python、mysql、java
<p>您应该将类定义更改为:</p>
<pre><code>class CurrencyDoesntExistError(BaseException):
...
</code></pre>
<p>文件:<a href="https://docs.python.org/3.1/tutorial/classes.html#inheritance" rel="nofollow">https://docs.python.org/3.1/tutorial/classes.html#inheritance</a></p>