in line 21, change `f = mmap.mmap(o.fileno(), 0, port=mmap.PORT_READ)` to `f = mmap.mmap(o.fileno(), 0, access=mmap.ACCESS_READ)` can work well
in line 21, change
f = mmap.mmap(o.fileno(), 0, port=mmap.PORT_READ)to
f = mmap.mmap(o.fileno(), 0, access=mmap.ACCESS_READ)can work well