如何在Python中找到列表的平均值?

[1, 2, 3, 4]  ⟶  2.5

当前回答

你可以为平均值,使用率做一个函数:

average(21,343,2983) # You can pass as many arguments as you want.

代码如下:

def average(*args):
    total = 0
    for num in args:
        total+=num
    return total/len(args)

*args允许任意数量的答案。

其他回答

对于Python 3.8+,使用统计信息。浮点数稳定性的平均值。(快)。

对于Python 3.4+,使用统计信息。平均数值稳定性与浮子。(慢)。

xs = [15, 18, 2, 36, 12, 78, 5, 6, 9]

import statistics
statistics.mean(xs)  # = 20.11111111111111

对于较旧版本的Python 3,请使用

sum(xs) / len(xs)

对于Python 2,将len转换为浮点数以获得浮点除法:

sum(xs) / float(len(xs))
xs = [15, 18, 2, 36, 12, 78, 5, 6, 9]
sum(xs) / len(xs)
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)

结合上面的几个答案,我提出了以下与reduce一起工作的方法,并且不假设你在reduce函数中有L可用:

from operator import truediv

L = [15, 18, 2, 36, 12, 78, 5, 6, 9]

def sum_and_count(x, y):
    try:
        return (x[0] + y, x[1] + 1)
    except TypeError:
        return (x + y, 2)

truediv(*reduce(sum_and_count, L))

# prints 
20.11111111111111

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。)