code: def currency_pair(code):
      '''Construct a :class:`ccy_pair` from a six letter string.'''
      c = str(code)
      c1 = currency(c[:3])
      c2 = currency(c[3:])
      return ccy_pair(c1, c2f currency_pair(code):
      '''Construct a :class:`ccy_pair` from a six letter string.'''
      c = str(code)
      c1 = currency(c[:3])
      c2 = currency(c[3:])
      return ccy_pair(c1, c2)
docs: Construct a :class:`ccy_pair` from a six letter string.