Slicing a file in Python
Converting one object to a mutable object does incur data copying. You can directly read the file to a bytearray by using:
f = open(FILENAME, 'rb')data = bytearray(os.path.getsize(FILENAME))f.readinto(data)
There is a string to bytearray conversion, so there is potential performance issue.
bytearray is an array, so it can hit the limit of PY_SSIZE_T_MAX/sizeof(PyObject*). For more info, you can visitHow Big can a Python Array Get?
You could do this little hack.
import mmapclass memmap(mmap.mmap): def read_byte(self): return ord(super(memmap,self).read_byte())Create a class that inherits from the mmap class and overwrites the default read_byte that returns a string of length 1 to one that returns a int. And then you could use this class as any other mmap class.
I hope this helps.