code: def satoshi_to_currency(num, currency):
      
      return '{:f}'.format(
          Decimal(
              num / Decimal(EXCHANGE_RATES[currency]())
          ).quantize(
              Decimal('0.' + '0' * CURRENCY_PRECISION[currency]),
              rounding=ROUND_DOWN
          ).normalize()
      )
docs: Converts a given number of satoshi to another currency as a formatted
      string rounded down to the proper number of decimal places.
  
      :param num: The number of satoshi.
      :type num: ``int``
      :param currency: One of the :ref:`supported currencies`.
      :type currency: ``str``
      :rtype: ``str``