Answer by Sylvain Leroux for Python subprocess: wait for command to finish before starting next one?

Normally, subprocess.call is blocking.

If you want non blocking behavior, you will use subprocess.Popen. In that case, you have to explicitly use Popen.wait to wait for the process to terminate.

See https://stackoverflow.com/a/2837319/2363712

BTW, in shell, if you wish to chain process you should use && instead of ; -- thus preventing the second command to be launched if the first one failed. In addition, you should test the subprocess exit status in your Python program in order to determine if the command was successful or not.