Daniel Arbuckle's Mastering Python

Subprocess and its variants

There are six objects in the subprocess package that are of particular interest. Three of them are the call, check_call, and check_output functions, which are three variants on the same basic idea:

from subprocess import call, check_call, check_output

These three objects run a program, wait for it to terminate, and then tell us something about what the program did:

• The call function returns the program's exit code, which is an integer that has a program-defined meaning, which is usually used to know whether the program has succeeded or failed.
• The check_call function raises an exception if the program's exit code is non-zero, which, by convention, means that it exited with an error.
• The check_output function ...