os.popen() was deprecated in Python 2.6 but it does still exist in Python 3.3. The function is no more documented: there is an entry in os documentation, but the entry is not in the index, and it has a reference to the "file object creation" section which doesn't have an paragraph about os.popen().

I prefer subprocess.Popen() over os.popen() because subprocess has much more options to control the child process creation (eg. change the current directory), it closes all files by default (which is more secure), it restores the signal handlers, etc.

I don't know if we can directly remove os.popen() from Python 3.3, because it is no more marked as deprecated in Python 3!