Efficient Way To Transpose The Bit Of An Integer In Python?

Consider a 6 bits integer x = a b c d e f that should be transpose to three integers of 2 bits as follows x1 = a d x2 = b e x3 = c f What is an efficient way to do this in pyth

Solution 1:

This should work:

mask = 0b100100

for i in range(2, -1, -1):
    tmp = x & mask
    print(((tmp >> 3 + i) << 1) + ((tmp & (1 << i)) >> i))
    mask >>= 1

The first mask extracts only a and d, then it is shifted to extract only b and e and then c and f.

In the print statement the numbers are either x00y00 or 0x00y0 or 00x00y. The (tmp >> 3 + i) transforms these numbers into x and then the << 1 obtains x0. The ((tmp & (1 << i)) >> i)) first transforms those numbers into y00/y0 or y and then right-shifts to obtain simply y. Summing the two parts you get the xy number you want.

Solution 2:

Slices will work if your working with strings ( bin(x) ).

>>>>>>HInt = 'ABCDEFGHIJKLMNO'>>>x = []>>>for i in [0, 1, 2]:
    x.append(HInt[i::3])


>>>x[0]
'ADGJM'
>>>x[1]
'BEHKN'
>>>x[2]
'CFILO'
>>>