Question

I would like to be able to call two (or more) commands within python but I would like to make sure that the first is finished before the second starts. Is that possible with subprocess? For example:

subprocess.call("script1 input1 > out", shell=True)

and when that command finishes:

subprocess.call("script2 out>out2", shell=True)

or is there a better way?

Answer 1

A call to subprocess.call blocks until the command completes. From the documentation:

Wait for command to complete, then return the returncode attribute.

A similar option that also waits for completion is subprocess.check_call. The difference between call and check_call is that the latter raises an exception for a nonzero return code, whereas the former returns the return code for all cases.