如何从列表末尾移动到Python列表的开头？

Question

如何从列表的后两个值中获取列表的第一个值。

例如，我有一个列表：

list1 = ['a','b','c','d','y','z']
# I know that going from 'a' to 'y' is using negatives,
n = 0 - 2 
list1[n]
# This will give the value of 'y'

# but how do I do the opposite? 'y' to 'a' ?
# not fetching the values from 'y' to 'a', instead, traversing from 'y' to 'a'

Answer 1

如果您需要从'y'到'a'之间的值：

>>> list1[n::-1]
['y', 'd', 'c', 'b', 'a']

n-新列表的开始，-1-步骤

Answer 2

i = (j + 2) % n
# where j is the index of 'y' 

Answer 3

这应该可以解决问题。列表-2的开始和步骤-1

li = ['a','b','c','d','y','z']
print(li[-2::-1])
#['y', 'd', 'c', 'b', 'a']