python operation on all slice elements code example

Example 1: python slice an array

a[start:stop]  # items start through stop-1
a[start:]      # items start through the rest of the array
a[:stop]       # items from the beginning through stop-1
a[:]           # a copy of the whole array
Example:
>>> a = [1, 2, 3, 4, 5, 6, 7, 8]
>>> a[1:4]
[2, 3, 4]

Example 2: python3 slice

# array[start:stop:step]

# start = include everything STARTING AT this idx (inclusive)
# stop = include everything BEFORE this idx (exclusive)
# step = (can be committed) difference between each idx in the sequence

arr = ['a', 'b', 'c', 'd', 'e']

arr[2:] => ['c', 'd', 'e']

arr[:4] => ['a', 'b', 'c', 'd']

arr[2:4] => ['c', 'd']

arr[0:5:2] => ['a', 'c', 'e']

arr[:] => makes copy of arr