def compute(self):
        experiment = self.get_input('experiment')

        # python -m reprounzip.plugins.vistrails <unpacker> <target> <run_id>
        # --input-file <na>:<a> --output-file <nb>:<b> --cmdline <c>
        if configuration.check('reprounzip_python'):
            python = configuration.reprounzip_python
        else:
            python = 'python'

        environ = dict(os.environ)
        removed = []
        for bad_var in ('PYTHONPATH', 'PYTHONHOME'):
            if bad_var in os.environ:
                removed.append(bad_var)
                del environ[bad_var]
        if removed:
            warnings.warn("Removing variables from environment before "
                          "calling reprounzip: %s" % ' '.join(removed))
        if (platform.system() == 'Darwin' and
                '/usr/local/bin' not in environ['PATH'].split(os.pathsep)):
            environ['PATH'] += os.pathsep + '/usr/local/bin'

        stdout = self.interpreter.filePool.create_file(prefix='vt_rpz_stdout_',
                                                       suffix='.txt')
        stderr = self.interpreter.filePool.create_file(prefix='vt_rpz_stderr_',
                                                       suffix='.txt')

        args = [python, '-m', 'reprounzip.plugins.vistrails',
                REPROUNZIP_VISTRAILS_INTERFACE_VERSION,
                experiment.unpacker, experiment.path,
                self.get_input('run_number') % '%d']
        for name in self.input_ports_order:
            if self.has_input(name):
                args.append('--input-file')
                args.append('%s:%s' % (name, self.get_input(name).name))
        output_ports = []
        for name in self.output_ports_order:
            f = self.interpreter.filePool.create_file(prefix='vt_rpz_out_')
            args.append('--output-file')
            args.append('%s:%s' % (name, f.name))
            output_ports.append((name, f))

        with open(stdout.name, 'wb') as stdout_fp:
            with open(stderr.name, 'wb') as stderr_fp:
                proc = subprocess.Popen(args,
                                        stdout=stdout_fp, stderr=stderr_fp,
                                        env=environ)
                proc.wait()

        with open(stderr.name, 'rb') as stderr_fp:
            while True:
                chunk = stderr_fp.read(4096)
                if not chunk:
                    break
                sys.stderr.write(chunk)

        if proc.returncode != 0:
            raise ModuleError(self,
                              "Plugin returned with code %d" % proc.returncode)

        for name, file in output_ports:
            self.set_output(name, file)

        self.set_output('experiment', experiment)
        self.set_output('stdout', stdout)
        self.set_output('stderr', stderr)
dataset/ETHPy150Open VisTrails/VisTrails/vistrails/packages/reprounzip/init.py/Run.compute/swapped operands of `%`