如何获得RecycleView的滚动坐标？(How is it possible get scroll coordinates of a RecycleView?)

 您可以简单地测试元组是否为“假”，即为空。 如果是，请返回您的特殊值： 
 
def max_steps(step_records):
    if not step_records:
        return None
    tuplemax = max(step_records, key = lambda x:x[1])
    return(tuplemax[1])
 
 但是，不是返回None或其他特殊值，而是提出一个特定的异常，让用户确切地知道出了什么问题： 
 
def max_steps(step_records):
    if not step_records:
        raise ValueError('"step_records" may not be empty')
    tuplemax = max(step_records, key = lambda x:x[1])
    return(tuplemax[1])

You can simply test if the tuple is "falsy" i.e empty. If it is, return your special value:
 
def max_steps(step_records):
    if not step_records:
        return None
    tuplemax = max(step_records, key = lambda x:x[1])
    return(tuplemax[1])
 
However, rather than returning None or some other special value, it would be better to raise a specific exception letting the user know exactly what went wrong:
 
def max_steps(step_records):
    if not step_records:
        raise ValueError('"step_records" may not be empty')
    tuplemax = max(step_records, key = lambda x:x[1])
    return(tuplemax[1])