使用计算PYTHON在while循环中设置新变量

debugcn 发表于 Dev

奥利

我正在运行总体模型，总是错误的数字，因为我将变量设置为新值，但是当我想使用旧变量时，循环会自动更新并使用新变量。

juvenile_population = 10
adult_population = 10
senile_population = 1
juvenile_survival = 1
adult_survival = 1
senile_survival = 0
birth_rate = 2
generations = 5


counter = 0
while counter < generations:
    juvenile_population = adult_population * birth_rate
    adult_population = juvenile_population * juvenile_survival
    senile_population = (adult_population * adult_survival) (senile_population * senile_survival)
    total_population = juvenile_population + adult_population + senile_population



    print("Juvenile: ",juvenile_population)
    print("Adult: ",adult_population)
    print("Senile: ",senile_population)
    print("Total: ",total_population)
    counter += 1

一位朋友说要设置新的命名变量，但是在一个循环之后，您是否会再次遇到相同的问题？我希望变量能够更新，但是只有在它们被打印之后才更新，如果那是有道理的。有什么建议么？

迈克尔_j_ward

对于@Selcuk，您可以直接使用变量解包，但是即使格式更好，它看起来也很笨拙：

juvenile_population, adult_population, senile_population, total_population = (adult_population * birth_rate,
                                                                             juvenile_population * juvenile_survival,
                                                                             (adult_population * adult_survival) (senile_population * senile_survival), 
                                                                             juvenile_population + adult_population + senile_population)

我的建议是要么编写一个辅助函数，然后将“ like”值保留在字典中，如下所示：

populations = {'juvenile':  10,
               'adult':     10,
               'senile':    1
               }
survivals = {'juvenile':    1,
             'adult':       1,
             'senile':      0}
birth_rate = 2
generations = 5

def update_population(pops):
    juvie = pops['adult'] * birth_rate
    adults = pops['juvenile'] * survivals['juvenile']
    seniles = pops['adult'] * survivals['adult'] + (pops['senile'] * survivals['senile'])
    return {k:v for k,v in zip(['juvenile','adult','senile'],[juvie,adults,seniles])}

counter = 0
while counter < generations:
    populations = update_population(populations.copy())
    total_population = sum(populations.values())



    print("Juvenile: ",populations['juvenile'])
    print("Adult: ",populations['adult'])
    print("Senile: ",populations['senile'])
    print("Total: ",total_population)
    counter += 1

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