slicing

定义

slicing extracts a series of characters from a string.

A slice [m:n] would therefore be read as “from characters m up to but not including characters n”.

how it works

‘MNKMDLVADVAEKTDLSKAKATEVIDAVFA’[0:9:3]

‘MMV’

从0位开始，每隔三位slicing一个str,直到第9位结束

‘MNKMDLVADVAEKTDLSKAKATEVIDAVFA’[16:0:-4]

‘SKDD’

从第16位开始，反向每隔4位slicing一个str，直到0位结束.

‘NMKMDLVADVAEKTDLSKAKATEVIDAVFA’[1:4]
‘MKM’

包括[1],不包括[5]

‘MNKMDLVADVAEKTDLSKAKATEVIDAVFA’[16::-3]

‘STAADN’

s = ‘abcdefgh’
s[::-1]

‘hgfedcba’

可视作“翻转”

s[::2]

‘aceg’

可视作隔一个取一个的操作