def unbind(topic, func):
    """
    Remove receiver function
    """
    if topic in _receivers:
        receivers = _receivers[topic]
        for i in range(1-len(receivers), -1, -1):
            nice, f = receivers[i]
            if (callable(func) and f['func'] == func) or (f['func_name'] == func):
                del receivers[i]
                return
dataset/ETHPy150Open limodou/uliweb/uliweb/core/dispatch.py/unbind/swapped operands of `-`