Python列表切片范围

Question

I am a new Python learner. I was stopped by some codes like below:

return ['FizzBuzz'[i%-3&-4:i%-5&8^12]or`i`for i in range(1,n+1)]

Especially what does it mean: [i%-3&-4:i%-5&8^12]

Thank you so much!

Answer 1

: is the range symbol, meaning give me the list elements between start and end in list[start:end] .

% is the modulo operator, & is the binary (bit-wise) and operator, so the first part:

i%-3&-4

is equal to mod(i, -3) & -4

^ is the exclusive or operator, so the second part:

i%-5&8^12

is equal to mod(i, -5 ) & 8^12

The modulo operator yields the remainder from the division of the first argument by the second.

If you need to know more about python binary (bit-wise) operators look here

As stated in the comments, without the back-tics `` , the last part after the or statement returns a range from 1 to n+1 , if the resulting fist list is empty.

The back ticks, in that statement is Python2 syntax for the repr() function. See repr documentation for more info