为什么我的代码会给我错误Attribute error: 'list' object has no attribute 'gainWeight'？
班级代码：
class Pig():
def __init__(self, name, age, weight, value):
self.name = name
self.age = age
self.weight = weight
self.value = value
def Weight(self):
self.weight = randrange(50,250)
def growOlder(self):
self.age += 1
def gainWeight(self, weight):
self.weight += 5
def runAndGainValue(self):
self.value += 5
def __str__(self):
a = self.name + " "
a += str(self.age) + " "
a += str(self.weight) + " "
a += str(self.value) + " "
return a
以及主程序中的代码：
def work_function():
work = input("What do you want to do for work today?"
"\nPress 1 to feed your animals"
"\nPress 2 to take them out in the yard"
"\nPress 3 to your animals to sleep"
"\nPress 4 to go back to main menu.\n")
if work == "1":
yourfarm.printAnimals()
print ("are all very happy to be fed and have gained some weight!\nLook at the weight now and see for yourself!")
p.gainWeight(+5)
#Here is where the problem lies.
yourfarm.printAnimals()
p 是我的动物物品的列表。
我不知道为什么我会收到这个错误。