>>> get_average_club_count(P2C)
1.6
"""
average = 0
summ = 0
for key in person_to_clubs:
summ = sum + len(person_to_clubs[key])
average = sum / len(person_to_clubs)
我正在使用的字典：
当我尝试执行docstring示例时得到的回报：
summ = sum + len(person_to_clubs[key])
builtins.TypeError: unsupported operand type(s) for +: 'builtin_function_or_method' and 'int'
sum是一个内置函数，因此不能将其用作变量名。命名summ也不是一个很好的解决方法，因为您容易混淆自己（就像我认为的那样）。也许total？
total = 0.0
for person in person_to_clubs:
total += len(person_to_clubs[person])
return total / len(person_to_clubs)
我相信您在变量名中缺少了一个“ m”！
我会说正确的代码是：
def get_average_club_count(person_to_clubs: Dict[str,List[str]]) -> float:
"""Return the average number of clubs that a person in person_to_clubs
belongs to.
>>> get_average_club_count(P2C)
1.6
"""
average = 0
summ = 0
for key in person_to_clubs:
summ = summ + len(person_to_clubs[key])
average = summ / len(person_to_clubs)
错误来自以下事实：sum是Python中的内置函数，而summ是您定义的局部变量。