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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def dbf_asdict(fn, usecols=None, keystyle='ints'):
 """Return data from dbf file fn as a dict. fn: str The filename string. usecols: seqence The columns to use, 0-based. keystyle: str 'ints' or 'names' accepted. Should be 'ints' (default) when this function is given to a ChannelPack as loadfunc. If 'names' is used, keys will be the field names from the dbf file. """


    if keystyle not in ['ints', 'names']:
        raise ValueError('Unknown keyword: ' + str(keystyle))

    with open(fn, 'rb') as fo:
        rit = dbfreader(fo)
        names = rit.next()
        specs = rit.next()      # NOQA
        R = [tuple(r) for r in rit]

    def getkey(i):
        if keystyle == 'ints':
            return i
        else:
            return names[i]

    R = zip(*R)
    d = dict()
    for i in usecols or range(len(names)):
        # d[getkey(i)] = R['f' + str(i)]  # Default numpy fieldname
        d[getkey(i)] = np.array(R[i])
    return d