String slicing in python from reverse - Printable Version +- Python Forum (https://python-forum.io) +-- Forum: Python Coding (https://python-forum.io/forum-7.html) +--- Forum: General Coding Help (https://python-forum.io/forum-8.html) +--- Thread: String slicing in python from reverse (/thread-17918.html) |
String slicing in python from reverse - ift38375 - Apr-29-2019 Hi, I am newbie in this python fourm portal and need some help from experts side. Suppose i declare string variable i.e name = "david" and perform name[0:3] then it prints "dav". But when i was trying to declare name[3:0] then it shows blank ? how can i take output as "vad" ? is it possible or not ? KS RE: String slicing in python from reverse - perfringo - Apr-29-2019 With code name[3:0] you give Python an order: "give me letters on indices starting from 3 up to 0 which is first to be excluded". As you can't go up 3 -> 0 then there is no slice.In order to go 'down' you must instruct Python to do so, and also keep in mind that last indice in slice will be excluded: >>> name = 'david' >>> name[2:0:-1] # -1 instructs Python to 'step down' 'va' # letter with index 0 is excluded >>> name[2::-1] 'vad' >>> name[2:None:-1] # this is same as previous but with explicit NoneMore information about slicings in Python documentation: Documentation >>> Glossary >>> slice Documentation >>> The Python Standard Library >>> Built-in Functions >>> slice() The Python Language Reference >>> 6. Expressions >>> 6.3. Primaries >>> 6.3.3. Slicings |