Question

Is there a way in numpy to create an array of booleans that uses just 1 bit for each entry?

The standard np.bool type is 1 byte, but this way I use 8 times the required memory.

On Google I found that C++ has std::vector<bool>.

Answer 1

You might like to take a look at bitstring (documentation here).

If you create a ConstBitArray or ConstBitStream from a file then it will use mmap and not load it into memory. In this case it won’t be mutable so if you want to make changes it will have to be loaded in memory.

For example to create without loading into memory:

>>> a = bitstring.ConstBitArray(filename='your_file')

or

>>> b = bitstring.ConstBitStream(a_file_object)