Iterate through blocks of bits from a number using python generator.

bitstream.py

def bitstream(x: int, length: int, block_size: int):
  assert length > 0 and block_size > 0, "Unsupported parameters"

  mask = int("1" * block_size, 2)

  for i in range(length):
    block = x & mask
    x >>= block_size

    yield block
    
# Example usage

if __name__ == "__main__":
  x = 0b1101_1111_1010_0001

  bits = bitstream(x, 4, 4)
 
  for block in bits:
    print(f"{block:>04b}")

# Output
#
# 0001
# 1010
# 1111
# 1101