python list iteration over a sequence of numbers with "breaking points"

Question

I have a list of numbers :

list = [1,2,3,1,2,3,4,1,2,3,4,5,1,2,3,4,5,6,7,8]

I would like through iteration to take all the numbers of every breaking point. Let's say from 3 to 1 i want to keep 3, from 4 to 1 i want to keep 4 and keep also the last number of the list and append it to a new list. I would like to have an output:

new_list = [3,4,5,8]

Answer 1

list = [1,2,3,1,2,3,4,1,2,3,4,5,1,2,3,4,5,6,7,8]
new_list = []

last_index = len(list)-1

#Iterate till last but one-element
for i in range(last_index):
    #If the number is greater than the next number, append it
    if list[i] > list[i+1]:
        new_list.append(list[i])

#The last element will come in the list even if it is smaller than its previous number
new_list.append(list[last_index])

print(new_list)