Transform a sentence using the NATO spelling alphabet.

    :param sentence: input sentence
    :param pad: default ``' '``
    :param format: default ``telephony``, options ``telephony`` or ``phonetic``

    >>> print(nato('Python'))
    papa yankee tango hotel oscar november

    >>> print(nato('Python', format='phonetic'))
    pah-pah yang-key tang-go hoh-tel oss-cah no-vem-ber

def nato(sentence, pad=' ', format='telephony'):
    '''
    Transform a sentence using the NATO spelling alphabet.

    :param sentence: input sentence
    :param pad: default ``' '``
    :param format: default ``telephony``, options ``telephony`` or ``phonetic``

    >>> print(nato('Python'))
    papa yankee tango hotel oscar november

    >>> print(nato('Python', format='phonetic'))
    pah-pah yang-key tang-go hoh-tel oss-cah no-vem-ber

    '''
    try:
        return '' + ALPHABET['nato'][format](sentence, pad)
    except KeyError:
        raise TypeError('Unsupported NATO alphabet "%s"' % (format,))