[Tutor] subprocess.call list vs. str argument

[Danny Yoo]

Last comment (apologies for being so fragmented!).  I don't know why
the literal strings there are raw there.  Altogether, I'd expect:

#############################################
cmd1 = ['sphinx-apidoc',
       '-f',
       '-F',
       '-H', title,
       '-A', author,
       '-V', version,
       '-o', output_dir,
       input_dir]
retcode = subprocess.call(cmd1, shell=False)
#############################################