How to get time (milisecond) of a python IO execution

[Skip Montanaro]

I'm not familiar with how Windows works, but I wouldn't be surprised
if it caches directory information. (Unix systems certainly would.)
You probably aren't really doing much actual I/O to get the size of a
file after the first run. Also, you probably want to subtract the time
it takes to execute a no-op function:

    def noop(): pass

to eliminate the overhead of calling your main function.

Skip