Question

我无法弄清楚如何取x（从下面的代码中）并将其添加到自身以获得总和，然后除以等级数。课堂上给出的例子是4个等级，数字是3,4,1和2.平均等级应该是2.5，但我似乎无法做到正确！

number_of_ratings = eval(input("Enter the number of difficulty ratings as a positive integer: "))       # Get number of difficulty ratings
for i in range(number_of_ratings):      #   For each diffuculty rating
    x = eval(input("Enter the difficulty rating as a positive integer: "))      # Get next difficulty rating
average = x/number_of_ratings
print("The average diffuculty rating is: ", average)

Answer 1

您的代码不会添加任何内容，只会在每次迭代中覆盖x。可以使用+=运算符向变量添加内容。另外，请勿使用eval：

number_of_ratings = int(input("Enter the number of difficulty ratings as a positive integer: "))
x = 0
for i in range(number_of_ratings):
    x += int(input("Enter the difficulty rating as a positive integer: "))
average = x/number_of_ratings
print("The average diffuculty rating is: ", average)

Answer 2

try:
    inp = raw_input
except NameError:
    inp = input

_sum = 0.0
_num = 0
while True:
    val = float(inp("Enter difficulty rating (-1 to exit): "))
    if val==-1.0:
        break
    else:
        _sum += val
        _num += 1

if _num:
    print "The average is {0:0.3f}".format(_sum/_num)
else:
    print "No values, no average possible!"

如何在Python中获取范围函数中所有数字的总和？

2 个答案: