无法在内部和外部 for 循环之间传递变量中的值 python 3.3

Question

我正在尝试使用 TeamTreehouse 学习订阅和这本从编程逻辑和设计开始的书来尝试学习编程和 python。请不要开枪打死我，我在重复结构方面遇到了困难！

目标：我试图在外部 for 循环中收集用户的输入。每次外循环迭代计算，内循环将迭代12次；获取每个月的降雨量。然后外循环；显示整个时间段（1 年或 7 年等）的月数、总降雨量英寸和每月平均降雨量。

我正在阅读有关按引用或按值传递值的内容，发现 python 具有可变和不可变数据类型（其中 int 是不可变数据类型），因此我不能简单地在两者之间传递数据for 循环从我的理解。那么我该如何让它发挥作用呢？虽然我不明白如何从列表中得出平均值，但我已经向我建议了一个列表，因为坦率地说，到目前为止，teamTreehouse 或我的书的第 4 章都没有涉及它。 http://en.wikibooks.org/wiki/Python_Programming/Data_Types

错误：无法将数据从内部嵌套循环变量 rainTotal 传输到外部循环 rainTotal。

代码：

#//////MAIN PROGRAM START//////

#//////VARIABLE DECLARATION//////
totalMonths=0
rainAverage=0
rainFall=0
rainTotal=0
#//////VARIABLE DECLARATION//////

#//////USER INPUT FUNCTION//////
def userInput():
    years=0
    months=12
#////don't understand how to function properly
#    monthly_rain = []
#////don't understand how to function properly
    print('This program will calculate the average rainfall over a period of years.')
    years=int(input("Please provide the number of years to calculate rainfall for."))
    for i in range(1, years + 1):
    #////////////////testing variable values correct////////////////
    #Placeholder
    #////////////////testing variable values correct////////////////
#//////USER INPUT FUNCTION//////
        for i in range(1, months + 1):
            rainTotal=int()
            monthlyRainFall=int(input("Please provide the rainfall in inches for month number " + str(i) + str(": ")))
#////don't understand how to function properly
#            monthly_rain.append(monthlyRainFall)
#////don't understand how to function properly
            rainTotal = rainTotal + monthlyRainFall
            rainAverage=rainTotal/months
            #//////testing variable <> value assignment/////
#///////// python code references/////////////
#            print('Calculating for a total number of', totalMonths, 'months.')
#            print('Months\t\t\t' + 'Average Rainfall')        
#            print(rain, '\t\t\t\t\t', i)
#/////////format references/////////////
    print("There was a total of ", (years*months), "months calculated.")
    print("The accumulative total of rainfall was ", rainTotal, " inches!")
    print("Average Rainfall per month:", rainTotal/(years*months))
# after the inner loop runs the following should display

#//////CALLING FUNCTION//////
userInput()
#//////CALLING FUNCTION//////

Answer 1

如前所述 - 请详细说明您收到的错误。但是通过查看您的代码，在进入内部循环之前尝试定义 rainTotal 。即：

for i in range(1, years + 1): rainTotal=int() #here for i in range(1, months + 1):

无法在内部和外部 for 循环之间传递变量中的值 python 3.3

Inability to pass values in variable between inner and outer for loops python 3.3

for-loop

global-variables

pass-by-reference

nested-loops

python-3.3