int_to_bytes.py

if signed:
    if value < 0:
        bits_required = abs(value + 1).bit_length()
    else:
        bits_required = value.bit_length()
    if bits_required % 8 == 0:
        bits_required += 1
else:
    bits_required = value.bit_length()
width = math.ceil(bits_required / 8) or 1
return value.to_bytes(width, byteorder='big', signed=signed)

I think it could be simplified to:

bits_required = value.bit_length()

if signed:
    if value < 0:
        bits_required = abs(value + 1).bit_length()
    if not bits_required % 8:
        bits_required += 1

width = (bits_required + 7) // 8 or 1
return value.to_bytes(width, byteorder='big', signed=signed)