def get_currency_ratio(ori_curr, dest_curr):
if ori_curr != "PLN":
url = f"http://api.nbp.pl/api/exchangerates/rates/A/{ori_curr.lower()}/"
response = requests.get(url)
ori_ratio = response.json()['rates'][0]['mid']
else:
ori_ratio = 1
if dest_curr != "PLN":

url =

f"http://api.nbp.pl/api/exchangerates/rates/A/{dest_curr.lower()}/"
response = requests.get(url)
dest_ratio = response.json()['rates'][0]['mid']
else:
dest_ratio = 1
ratio = float(ori_ratio)/float(dest_ratio)
return ratio