how to find index of element in list in python from last code example

Example 1: how to find last index of list in python

# Use an Index of -1
l = [1,2,3,4]
print(l[-1])
# Returns 4

Example 2: python last index of item in list

def list_rindex(li, x):
    for i in reversed(range(len(li))):
        if li[i] == x:
            return i
    raise ValueError("{} is not in list".format(x))