如何使3个函数在一个程序中运行

Question

要获得答案，请尽可能简单地避免使用任何过于先进的技术，因为我仍然在学习Python并且不想跳得太远......

对于def主程序，我试图在这个＆＃34; Main＆＃34;中运行所有3个函数，Summation和Multiply函数是自解释的，CreateIntList假设函数接受一个sentinel值（一个整数） ），和 它接受一个sentinal值（int）并返回一个整数列表。它会提示用户创建一个整数列表，使用提供的sentinel值作为用户输入的数字以退出列表的创建。

For each list:
o Tell the user which number list they are creating (starting at 1)
o Ask the user for their desired sentinel value
o Create a lists of integers (using the given sentinel value)
o Calculate the summation
o Calculate the product
o Print out:
 The entire list
 The summation of the list
 The product of the list



def summation(intlist):
    output = 0
    for x in range(len(intlist)):
        output += intlist[x]
    return output

def multiply(intlist):
    if len(intlist) == 0:
        output = 0
        return output
    else:
        output = 1
        for x in range(len(intlist)):
            output = intlist[x] * output
        return output

def createIntList(myInt):
    createlist = []
    myInt = int(input("What do you want the sentinel to be?"))
    addNum = None
 while myInt != addNum:
        addNum = input("Please enter a number, ", myInt, "to stop: ")
        createlist.append(addNum)
    return createlist

def main():
    print("Welcome to the Simple Math Helper")
    listIteration = int(input("How many list would you like to create? "))
    x = 0
    for x in range(len(listIteration)):
        print("Your are creating list #", x)
        createIntList(myInt)
        multiply(createIntList)
        summation(createIntList)
        x = x + 1
    print("Thank you for using the Simple Math Helper")


main()

预计输出：

Welcome to the Simple Math Helper
How many lists would you like to create? 1
You are creating list #1
What do you want the sentinel to be? 0
Please enter a number, 0 to stop: 1
Please enter a number, 0 to stop: 2
Please enter a number, 0 to stop: 3
Please enter a number, 0 to stop: 4
Please enter a number, 0 to stop: 5
Please enter a number, 0 to stop: 6
Please enter a number, 0 to stop: 7
Please enter a number, 0 to stop: 8
Please enter a number, 0 to stop: 9
Please enter a number, 0 to stop: 10
Please enter a number, 0 to stop: -9
Please enter a number, 0 to stop: -3
Please enter a number, 0 to stop: -1
Please enter a number, 0 to stop: 0
For the list [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, -9, -3, -1]
The summation is 42
The product is -97977600
Thank you for using the Simple Math Helper

Answer 1

Samira N已经给了您一些反馈，但您的代码还有许多其他问题。我评论了所有有错误的行并为您纠正了这些行。

def summation(intlist):
    output = 0  #you are correct, as you are using it below, you need to initialize beforehand
    #for x in range(len(intlist)): # see below for a better way to use list in a 'for'
    for x in intlist: # 'x' now represents the proper element inside the list, iterating each element
        #output += intlist[x] #see below on how to use 'x' with the new 'for'
        output += x
    return output

def multiply(intlist):
    if len(intlist) == 0:
        #output = 0 # no need for 'output'
        #return output # same
        return 0
    else:
        output = 1# same here, you are using output below, so you need to initialize beforehand. Nice!
        #for x in range(len(intlist)): # same as before, see below for a better way to use 'for' with lists
        for x in intlist:
            #output = intlist[x] * output # same as before, use 'x' instead of 'intlist[x]' with the new 'for'
            output = x * output
        return output

#def createIntList(myInt): #you are initializing myInt in the input, so you dont need it here
def createIntList():
    #createlist = [] # you should use better names for your variables
    new_list = []
    #myInt = int(input("What do you want the sentinel to be?")) # pick a better name for myInt
    sentinel = int(input("What do you want the sentinel to be?"))
    #addNum = None # same, better name
    number = None
    #while myInt != addNum: #see below for the 'while' with the new variable names
    while sentinel != number:
        #number = input("Please enter a number, ", sentinel, "to stop: ") # you need to use + to append, but you need to parse it to str as 'sentinel' is an int
        number = int(input("Please enter a number, " + str(sentinel) + "to stop: ")) # same you did with 'sentinel', need to add 'int(' so you make sure it returns a number
        #createlist.append(addNum) #same code below, but with the new variable names
        if sentinel != number: # so you don't add the sentinel to the list
            new_list.append(number)
    return new_list

def main():
    print("Welcome to the Simple Math Helper")
    listIteration = int(input("How many list would you like to create? "))
    #x = 0 # x is already being initialized/declared in the 'for' below
    #for x in range(len(listIteration)): # listIteration is already an int, so you don't need to use len()
    for x in range(listIteration):
        print("Your are creating list #", x+1) #x+1 because x starts as 0, +1 ensures it will show 'Your are creating list #1' and so on
        #createIntList(myInt) # you are calling the function with a variable that doesnt exist: myInt
        int_list = createIntList() # as createIntList returns something, lets use int_list to save the returned list
        #multiply(createIntList) # you need to send as paramter a variable (not the function itself)
        multiplication_output = multiply(int_list) # you are returning an int, so you need to store it somewhere
        #summation(createIntList) # send a variable, not the function
        sum_output = summation(int_list) # same as before store the return somewhere
        # x = x + 1 # no need for this, the 'for' does it already
        print("For the list ", int_list)
        print("The summation is ", sum_output)
        print("The product is ", multiplication_output)
    print("Thank you for using the Simple Math Helper")


main()

我试着按照你的要求保持简单：

  

要获得答案，请尽可能简单地避免使用任何过于先进的技术，因为我仍然在学习Python并且不想跳得太远......

但我会这样做：

def summation(int_list):
    return sum(int_list) #sum() is a pretty good built-in function :)

def multiply(int_list):
    if int_list: #better way to write 'if len(intlist) != 0:'
        output = 1
        for x in int_list:
            output = x * output
        return output
    else:
        return 0

def create_list(list_number):
    print('Your are creating list #{}'.format(list_number))
    new_list = []
    sentinel = int(input('What do you want the sentinel to be? '))
    number = None
    while number != sentinel:
        #str.format() is a function that I love.
        #Check it out: https://pyformat.info/
        number = int(
        input('Please enter a number ({} to stop): '.format(sentinel)))
        if number != sentinel:
            new_list.append(number)
    return new_list

def main():
    print('Welcome to the Simple Math Helper')
    listIteration = int(
    input('How many list would you like to create? '))

    for x in range(listIteration):
        int_list = create_list(x+1)
        multiplication_output = multiply(int_list)
        sum_output = summation(int_list)
        print('''For the list {}
The summation is {}
The product is {}'''.format(int_list, sum_output,multiplication_output))

    print('Thank you for using the Simple Math Helper')

main()