def test_remove(self): system_commands = [] def fake_system(cmd): system_commands.append(cmd) original_system = os.system os.system = fake_system filenames = [ 'archive.rar', 'archive.r00', 'archive.r01', 'archive.r02' ] archive = RarArchive('archive', './path', filenames) archive.remove() self.assertEquals(system_commands, [ 'rm -f ./path/archive.r00 ./path/archive.r01 ' './path/archive.r02 ./path/archive.rar' ]) os.system = original_system