string slicing third argument not working code example

Example 1: python string indexing

str = 'codegrepper'
# str[start:end:step]
#by default: start = 0, end = len(str), step = 1
print(str[:]) 		#codegrepper
print(str[::]) 		#codegrepper
print(str[5:]) 		#repper
print(str[:8]) 		#codegrep
print(str[::2]) 	#cdgepr
print(str[2:8]) 	#degrep
print(str[2:8:2]) 	#dge
#step < 0 : reverse
print(str[::-1]) 	#reppergedoc
print(str[::-3]) 	#rpgo
# str[start:end:-1]	means start from the end, go backward and stop at start
print(str[8:3:-1]) 	#pperg

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