<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def split_input(val, mapper=None):
    '''
    Take an input value and split it into a list, returning the resulting list
    '''
    if mapper is None:
        mapper = lambda x: x
    if isinstance(val, list):
        return list(map(mapper, val))
    try:
        return list(map(mapper, [x.strip() for x in val.split(',')]))
    except AttributeError:
        return list(map(mapper, [x.strip() for x in six.text_type(val).split(',')]))