why does all these code lines print the same?

Question

help me understand pls.
https://code.sololearn.com/cRNoy5C1NaJV/?ref=app

Answer 1

Please keep in mind that slicing can be a bit weired:

# 2. slice has descending order of start / stop and a therefor a negative step
print(I[1:3] + I[5:1:-1]) # res = [2, 3, 5, 4, 3]

# 2. slice has ascending order of start / stop and a positive step
print(I[1:3] + I[1:5:1]) # res = [2, 3, 2, 3, 4, 5]

Answer 2

Try running this variant to your code, I think it will answer your question

# why does all these code print the same? #Run the program
I = list((1,2,3,4,5))
print(I[5:1])

I = list((1,2,3,4,5))
print(I[4:2])

I = list((1,2,3,4,5))
print(I[3:2])

I = list((1,2,3,4,5))
print(I[5:2])
# but, if the numbers(list indentations) go from low to high it works in normal known way.
I = list((1,2,3,4,5))
print(I[1:3] + I[3:5])

Answer 3

If you want to go from higher to lower you have to specify the step in negative like that
I[5:3:-1]