擅长:python、mysql、java
<p>实例变量应该在<code>__init__</code>内部初始化</p>
<pre><code>class Quizzes:
def __init__(self):
self._grades = [] # Here, we initialize the list
def grades(self):
return self._grades # We can return the instance variable here
def gradeInsert(self, a): # No reason for a default argument here
self._grades.append(a) # Add the value to the list
</code></pre>