python - 如何捕获 python 中所有索引超出范围的错误？

Question

我是计算像素点之间的距离，只是在程序中做了一个鼠标回调函数，用于计算x和y坐标。

这是我试过的代码，

def distance():
    length = len(position)
    # Distance in terms of x
    distance_value = position[length-1][0] - position[length-2][0]
    # Distance in terms of y
    # distance_value = position[length-1][1] - position[length-2][1]

    print("Value of pixel is: " + str(distance_value))

IndexError: list index out of range.

Answer 1

我想您需要执行以下操作:

def distance():
    length = len(position)
    # Distance in terms of x
    try:
        distance_value = position[length-1][0] - position[length-2][0]
        print("Value of pixel is: " + str(distance_value))
    except IndexError as e:
        print('There is an error')
        print(str(e))