Python:在类继承中传递可选参数

Question

我不明白为什么我不能将可选参数设置为值。我总是收到一个空列表。我将参数设置为 Nonetype 以避免在那里使用可变类型。它是由于我的父类的疏忽而没有更新还是其他原因？

class Human:
def __init__(self,first,last,age,nicknames=None):
self.first =first
self.last = last
self.age = age
if nicknames is None:
self.nicknames = []
else:
self.nicknames = nicknames

class NFL_QB:
def __init__(self,td,comeback,lst=None):
self.td = td
self.comeback = comeback
if lst is None:
self.lst = []
else:
self.lst = lst

class College_QB:
def __init__(self,c_td,c_comeback):
self.c_td = c_td
self.c_comeback = c_comeback

class Player(Human,NFL_QB,College_QB):
def __init__(self,first,last,age,td,comebacks,c_td,c_comebacks,nicknames=None,lst=None):
Human.__init__(self,first,last,age,nicknames=None)
NFL_QB.__init__(self,td,comebacks,lst=None)
College_QB.__init__(self,c_td,c_comebacks)


ply = Player('tom','brady',42,532,55,32,21,['toutchdown tom'],[2016])

Answer 1

将参数传递给超类构造函数 :

class Player(Human,NFL_QB,College_QB):
def __init__(self,first,last,age,td,comebacks,c_td,c_comebacks,nicknames=None,lst=None):
Human.__init__(self,first,last,age,nicknames=nicknames) # You were passing `None` here
NFL_QB.__init__(self,td,comebacks,lst=lst)  # ...and here.
College_QB.__init__(self,c_td,c_comebacks)


ply = Player('tom','brady',42,532,55,32,21,['toutchdown tom'],[2016])
print(ply.__dict__)