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