Subprocess cp returns error – bufsize must be integer [duplicate]

You’ve got two problems:

1 – subprocess.call() expects a list of arguments, not multiple arguments:

#wrong
subprocess.call('cp', in, out)
#right
subprocess.call(['cp', in, out])

2 – in is a python reserved keyword, change it to something like inp:

#wrong
subprocess.call(['cp', in, out])
#right
subprocess.call(['cp', inp, out])