Phantom bit

[evglitvin]

Python 3.8, Ubuntu 20, bitarray was installed using pip

The problem is that when padding zeros added there might be trash in it

int.from_bytes(a[:10], byteorder='big') 1617 int.from_bytes(a[:10], byteorder='big') 1616 int.from_bytes(a[:10], byteorder='big') 1616 a[:10] bitarray('0000011001')

[ilanschnell]

Thank you for using bitarray and reporting this issue. What is happening here is that the int method .from_bytes() uses the memoryview of the bitarray object a[:10]. Whenever a[:10] is called, it returns a newly created bitarray object with uninitialized pad bits. Note that the pad bits are not always set to zero. However, when calling bitarray's .tobytes() method, the pad bits will be set to zero. So when calling the following, you will always get the same int value:

int.from_bytes(a[:10].tobytes(), byteorder='big')