class Currencies:
"""
Stores in use currencies and provides access to the individual objects.
"""
_CAD = Currency.CAD()
_USD = Currency.USD()
_EUR = Currency.EUR()
__instance = None
@staticmethod
def get_instance():
"""
Returns the instance of Currencies.
:return: Instance of Currencies..
"""
if Currencies.__instance is None:
Currencies()
return Currencies.__instance
def __init__(self):
"""
Singleton pattern for the Currencies class.
"""
if Currencies.__instance is None:
Currencies.__instance = self
def get_currency(self, option: str) -> Currency:
"""
Maps the option string to the desired currency and returns it.
:param option: String that maps to a respective currency.
:return: Currency object.
"""
valid = False
while not valid:
if option == "1":
return self._CAD
if option == "2":
return self._USD
if option == "3":
return self._EUR
else:
option = input(
"Invalid currency selection! Please try again.\n"
"Please select the currency you would like to perform "
"the transaction in:\n(1) CAD\n(2) USD\n(3) EUR\n")
