code: def convert(from_currency, to_currency, from_currency_price=1):
  	
  	get_cache()
  	from_currency, to_currency = validate_currency(from_currency, to_currency)
  	update_cache(from_currency, to_currency)
  	return ccache[from_currency][to_currency]['value'] * from_currency_price
docs: convert from from_currency to to_currency using cached info