it can not work on windows

[yanzixiang]

Got an error like this
AttributeError: module 'mmap' has no attribute 'MAP_SHARED'

after change this line

         self.raw = mmap.mmap(fd, fullsize, mmap.MAP_SHARED, mmap.PROT_READ)

to

           if sys.platform.startswith('win'):
                # Windows
                self.raw = mmap.mmap(fd, fullsize, access=mmap.ACCESS_READ)
            else:
                # Unix-like
                self.raw = mmap.mmap(fd, fullsize, mmap.MAP_SHARED, mmap.PROT_READ)

got an error like this
return struct.unpack_from('>H', self.raw,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: 'float' object cannot be interpreted as an integer

Could you assist in resolving this issue?

[vandry]

Your first change looks reasonable at a glance, but I have no means of testing it since I do not have that operating system to test with.