1 Answer. Popen is nonblocking. call and check_call are blocking. You can make the Popen instance block by calling its wait or communicate method.

What does subprocess run do?

The Subprocess. run method takes a list of arguments. When the method is called, it executes the command and waits for the process to finish, returning a “CompletedProcess” object in the end. The “CompletedProcess” object returns stdout, stderr, original arguments used while calling the method, and a return code.

What is the difference between subprocess call and run?

The main difference is that subprocess. run executes a command and waits for it to finish, while with subprocess. Popen you can continue doing your stuff while the process finishes and then just repeatedly call subprocess. communicate yourself to pass and receive data to your process.