Inserting a '0' bit into the middle of a bitsequence in python-CodePudding

This should be fairly simple, but I've yet to see a viable solution.

If I have a bit sequence (represented as an integer), how would I insert a 0 at index n?

For example:

insert(0b100101010101,4) -> 0b1001001010101

insert(0b101,3) -> 0b1010

insert(0b10001,2) -> 0b100001

EDIT: To clarify, I would like to do this without using vectors or strings (only bitwise operators)

CodePudding user response：

You would need to isolate the bits to the left and to the right of the insertion point, then shift the left part one position, and combine both parts again:

def insert(n, bit):
    length = n.bit_length()
    if bit > length:
        raise ValueError("argument out of range")
    right = n & ((1 << length - bit) - 1)
    return ((n - right) << 1)   right