当然，你可以使用内置函数，但如果你想创建自己的函数，你可以这样做。这里的技巧是使用~运算符将正数转换为负数。例如~2 -> -3和在Python中使用负in For list将从末尾开始计数。如果你有mid == 2，那么它会从开始取第三个元素，从结束取第三个元素。

def median(data):
    data.sort()
    mid = len(data) // 2
    return (data[mid] + data[~mid]) / 2

我为一组数字定义了一个中值函数

def median(numbers):
    return (sorted(numbers)[int(round((len(numbers) - 1) / 2.0))] + sorted(numbers)[int(round((len(numbers) - 1) // 2.0))]) / 2.0

只要两行就够了。

def get_median(arr):
    '''
    Calculate the median of a sequence.
    :param arr: list
    :return: int or float
    '''
    arr = sorted(arr)
    return arr[len(arr)//2] if len(arr) % 2 else (arr[len(arr)//2] + arr[len(arr)//2-1])/2

def median(array):
    """Calculate median of the given list.
    """
    # TODO: use statistics.median in Python 3
    array = sorted(array)
    half, odd = divmod(len(array), 2)
    if odd:
        return array[half]
    return (array[half - 1] + array[half]) / 2.0

import numpy as np
def get_median(xs):
        mid = len(xs) // 2  # Take the mid of the list
        if len(xs) % 2 == 1: # check if the len of list is odd
            return sorted(xs)[mid] #if true then mid will be median after sorting
        else:
            #return 0.5 * sum(sorted(xs)[mid - 1:mid + 1])
            return 0.5 * np.sum(sorted(xs)[mid - 1:mid + 1]) #if false take the avg of mid
print(get_median([7, 7, 3, 1, 4, 5]))
print(get_median([1,2,3, 4,5]))

以下是我在Codecademy的练习中得出的结论:

def median(data):
    new_list = sorted(data)
    if len(new_list)%2 > 0:
        return new_list[len(new_list)/2]
    elif len(new_list)%2 == 0:
        return (new_list[(len(new_list)/2)] + new_list[(len(new_list)/2)-1]) /2.0

print median([1,2,3,4,5,9])