def _preparse(args):
    task = None
    taskname = None
    while args:
        arg = args.pop(0)
        if '=' in arg:
            key, value = arg.split("=")
            try:
                environment.options.setdotted(key, value)
            except AttributeError:
                raise BuildFailure("""This appears to be a standalone Paver
tasks.py, so the build environment does not support options. The command
line (%s) attempts to set an option.""" % (args))
        elif arg.startswith('-'):
            args.insert(0, arg)
            break
        else:
            taskname = arg
            task = environment.get_task(taskname)
            if task is None:
                raise BuildFailure(taskname % "Unknown task: %s")
            break
    return task, taskname, args
dataset/ETHPy150Open paver/paver/paver/tasks.py/_preparse/swapped operands of `%`