Question

I’m doing some kind of complex operation, it needs the last line(s) of code has completed, then proceed to the next step, for example. I need to ensure a file has written on the disk then read it. Always, the next line of code fires while the file haven’t written on disk , and thus error came up. How resolve this?

Okay..

picture.save(path, format='png')
time.sleep(1)       #How to ensure the last step has finished
im = Image.open(path)

Answer 1

You do not need to do anything unless the previous operation is asynchronous. In your case, you should check picture.save’s documentation to see if it specifically define as asynchronous. By default everything is synchronize. Each line will complete before it continues to next operation.