Python Can't understand conditional statement in loop

Question

Need help in python. This code is from leetcode.com, one of the solutions for this problem and cannot understand conditional statement there, exactly the code "stack[-1][1]"

class Solution(object):

def dailyTemperatures(self, temps):

    if not temps:
        return []

    result = [0] * len(temps)
    stack = []

    for curr_idx, curr_temp in enumerate(temps):

        while stack and curr_temp > stack[-1][1]: # not clear, and I know, it is not a type of access to list element

            last_idx, last_temp = stack.pop()
            result[last_idx] = curr_idx - last_idx

        stack.append((curr_idx, curr_temp))

    return result

Answer 1

It is returning the second element of whatever is in the last index of stack

for instance, if the stack was a list of strings like

stack = ['abc','def','ghi']

than stack[-1][1] returns

stack[-1] <-- 'ghi'
stack[-1][1] <-- 'h'