为了使用reduce来获取运行平均值，您需要跟踪到目前为止所看到的元素总数。因为它不是列表中的一个普通元素，所以还必须向reduce传递一个要折叠成的额外参数。

>>> l = [15, 18, 2, 36, 12, 78, 5, 6, 9]
>>> running_average = reduce(lambda aggr, elem: (aggr[0] + elem, aggr[1]+1), l, (0.0,0))
>>> running_average[0]
(181.0, 9)
>>> running_average[0]/running_average[1]
20.111111111111111

我尝试使用上面的选项，但没有工作。 试试这个:

from statistics import mean

n = [11, 13, 15, 17, 19]

print(n)
print(mean(n))

使用过python 3.5

当Python有一个完美的cromulent sum()函数时，为什么要使用reduce()呢?

print sum(l) / float(len(l))

(float()在Python 2中强制Python执行浮点除法是必需的。)

numbers = [0,1,2,3]

numbers[0] = input("Please enter a number")

numbers[1] = input("Please enter a second number")

numbers[2] = input("Please enter a third number")

numbers[3] = input("Please enter a fourth number")

print (numbers)

print ("Finding the Avarage")

avarage = int(numbers[0]) + int(numbers[1]) + int(numbers[2]) + int(numbers [3]) / 4

print (avarage)

print reduce(lambda x, y: x + y, l)/(len(l)*1.0)

或者像之前写的那样

sum(l)/(len(l)*1.0)

1.0是为了确保你得到一个浮点除法

简单的解决方案是avmedii -lib

pip install avemedi_lib

而不是包括在你的剧本中

from avemedi_lib.functions import average, get_median, get_median_custom


test_even_array = [12, 32, 23, 43, 14, 44, 123, 15]
test_odd_array = [1, 2, 3, 4, 5, 6, 7, 8, 9]

# Getting average value of list items
print(average(test_even_array))  # 38.25

# Getting median value for ordered or unordered numbers list
print(get_median(test_even_array))  # 27.5
print(get_median(test_odd_array))  # 27.5

# You can use your own sorted and your count functions
a = sorted(test_even_array)
n = len(a)

print(get_median_custom(a, n))  # 27.5

享受。