与python中先前值和当前值之间的保存混淆

Question

我是python中的新手，我尝试制作一个简单的python脚本，在前一个值和当前值之间保存一个波动值。但我对此感到困惑..

假设一个波动值是位置

previous_value = position

current_value = position

如何使之前的值保存在下一个位置值之前？

Answer 1

previous_value,current_value = None,None  #initialize values outside the loop

for loop ... :
  previous_value = current_value   #storing last current value as previous value
  current_value = position         #storing current position as current value.

Answer 2

previous_value, current_value = current_value, position

Answer 3

Python赋值保证您可以在赋值的左侧和右侧使用相同的变量，并且还允许在单个语句中分配多个值：

previous, current = 0, 1
for i in range(10):
    previous, current = current, i