Python数组排序——日常学习记录

**程序的功能：**输入一个随机的数组，然后随机插入一个数字之后对数组进行排序。
这次遇到了一个数据类型转换的问题。

if __name__ == '__main__':
    n = int(input("Please Input the D is:\n"))
    a = []
    for i in range(n):
        a.append([])
        if i == n-1:
            a[i] = 0
        else:
            a[i].append(float(input("Please input the Number:")))
    print("Initial List:")
    for i in range(n):
        print(a[i])
    number = int(input("\n插入一个数字：\n"))
    end = a[n-2]
    if number > end:
        a[n-1] = number
    else:
        for i in range(n-1):
            if a[i] > number:
                tem1 = a[i]
                a[i] = number
                for j in range(i + 1, n):
                    tem2 = a[j]
                    a[j] = tem1
                    tem1 = tem2
                break
    print('排序后的列表为：')
    for i in range(n):
        print (a[i])
    print("插入新数后的列表为：")
    for i in range(n):
        print (a[i])

    # 排序
    for i in range(n):
        for j in range(i + 1, n):
            if a[i] > a[j]:
                temp3 = a[i]
                a[i] = a[j]
                a[j] = temp3
    print("排序后的列表为：")
    for i in range(n):
        print(a[i])

第一次输出结果提示：

Traceback (most recent call last):
  File "H:/Python/39.py", line 17, in <module>
    if number > end:
TypeError: '>' not supported between instances of 'int' and 'list'

根据提示将end = a[n-2]改为end = int(a[n-3])以后出来得第二次提示为

TypeError: int() argument must be a string, a bytes-like object or a number, not 'list'

之后将end = a[n-2]改为end = a[-3]同时在下面加了一行输出end的类型，出来的结果是

<class 'list'>
Traceback (most recent call last):
  File "H:/Python/39.py", line 18, in <module>
    if number > end:
TypeError: '>' not supported between instances of 'int' and 'list'

但是我在shell中运行的

>>> a = [2, 5, 6, 9, 7]
>>> a[-2]
9
>>> type(a)
<class 'list'>
>>> b = a[-2]
>>> b
9
>>> type(b)
<class 'int'>
>>> c = a[-3]
>>> type(c)
<class 'int'>

这是什么鬼啊（抓头发！）然后我就顺着一直往上查看a[]的输出类型，从最开始的for循环输入开始就一直是list的类型。所以将

a[i].append(float(input("Please input the Number:")))

改为

a[i] = int(input("Please input the Number:"))

然后就可以正常输出了。

Ps:当然排序的时候直接用Python中的.sort()即可。