过滤列表而不创建新列表?

“UnboundLocalError:赋值前引用的局部变量'Persons'。

你第一次提到 individuals

SeekWaterHole(individuals, lakes)

但它尚未在函数中定义,也未作为函数的输入提供。因此python不知道它引用了什么。

from random import randint
def day(numberOfDays):
individuals=''
days = 0
while days < numberOfDays:
    print(str(days) + " days")
    child = randint(1,100)
    #if child > 95:
        #IndividualGenerator(randint(1,2))
    individuals=[]//initialize the list before using it
    #SeekWaterHole(individuals, lakes)
    #rain(lakes)
    #DrinkWater(individuals, lakes)
    for r in range(len(individuals)):
        individuals[r].waterstore -= 1
    individuals = list(filter(lambda x: x.waterstore > 0,individuals))
    individualTotalWater = []
    for i in individuals:
        individualTotalWater.append(i.waterstore)
    #AmountWater = lakes[0].water
    #Logg = [AmountWater, sum(individualTotalWater), len(individuals)]
    #with open("NewCSVTestFile.csv", "a") as f:
    #        openfile = csv.writer(f, delimiter=",")
    #        openfile.writerow(Logg)
    #print("logg " + str(Logg))
    print()
    days += 1
day(10)