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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 altimeter(alt: Number, unit: str = 'inHg') -> str: """ Format altimeter details into a spoken word string """

    ret = 'Altimeter '
    if not alt:
        ret += 'unknown'
    elif unit == 'inHg':
        ret += core.spoken_number(alt.repr[:2]) + ' point ' + core.spoken_number(alt.repr[2:])
    elif unit == 'hPa':
        ret += core.spoken_number(alt.repr)
    return ret