直接在python中使用位

Question

I want to manipulate the binary number directly in python. For example I have decimal number 18. I was able to convert number into binary using

seed =bin(18)

but problem is I want to xor few of its bits.If I access this seed using array indexing I cant xor them as it is of type 'str'. How can simply take decimal number convert into binary and play with its bits?

Thanks in advance

Answer 1

You can use bitwise operators directly on numbers.

For instance 18 & 3 gets you 2 , 18 | 3 18 | 3 gets you 19 , 1 << 5 gets you 32 . The fact that the human readable representation when you print the number is a decimal number doesn't change the fact that at an underlying level the numbers are all just stored and operated on as binary numbers.

bin just gives you the binary representation of a number as a string. While that's useful for debugging or human output, you generally won't want to use it for bit manipulation directly.

Answer 2

You can use bitwise operations directly on integers. You can convert between binary strings and integers for printing/debugging by using bin as you already know, and converting a string to binary using int(binary_string, 2) .

seed = bin(18)  # 0b10010
bitmask = '01101'
xor_result = 18 ^ int(bitmask, 2)
print(bin(xor_result))  # 0b11111