#7.1.2
def r(filename):    #获取数据
    with open(filename, 'r') as f:
        return list(map(float, f.read().split()))

def a(x):    #平均值
    average_x = sum(x)/len(x)
    return "平均值:{:.0f}".format(average_x)

def f(x):    #标准差
    import numpy
    list2_f = numpy.var(x)  #numpy库的标准差公式
    return "标准差:{:.0f}".format(list2_f)

def z(x):    #中位数
    y = x
    length = len(y)
    sorted_nums = sorted(y)
    mid = length // 2

    if length % 2:
        result = sorted_nums[mid]
    else:
        left = sorted_nums[mid - 1]
        right = sorted_nums[mid]
        result = (left + right) / 2
    return f"中位数:{round(result)}"


nums = r('nums.txt')    #文件地址
print(nums)
nums_p = a(nums)
print(nums_p)
nums_b = f(nums)
print(nums_b)
nums_z = z(nums)
print(nums_z)


with open('new_nums.txt', 'w', encoding='utf-8') as new_nums:
    new_nums.write(nums_p + "\n")
    new_nums.write(nums_b + "\n")
    new_nums.write(nums_z + "\n")
    sorted_str = "排序后:" + " ".join(map(str, sorted(nums)))
    new_nums.write(sorted_str + "\n")