How to iterate over two dictionaries at once and get a result using values and keys from both

Question

def GetSale():#calculates expected sale value and returns info on the stock with              highest expected sale value
      global Prices
      global Exposure
              


        

Answer 1

Looking at your problem, I would suggest you to create generator expression that navigates the two dictionary in pairs and using max with a custom key to calculate sale price to evaluate expected_sale_price and the corresponding stock

Sample Data

Prices = dict(zip(range(10), ((randint(1,100), randint(1,100)) for _ in range(10))))
Exposure = dict(zip(range(10), ((randint(1,100), randint(1,100)) for _ in range(10))))

Sample Code

def GetSale(Prices, Exposure):
    '''Get Sale does not need any globals if you pass the necessary variables as
       parameteres
    '''
    from itertools import izip
    def sale_price(args):
        '''
        Custom Key, used with the max function
        '''
        key, (bprice, cprice), (risk, shares) = args
        return ( (cprice - bprice ) - risk * cprice) * shares

    #Generator Function to traverse the dict in pairs
    #Each item is of the format (key, (bprice, cprice), (risk, shares))
    Price_Exposure = izip(Prices.keys(), Prices.values(), Exposure.values())


    #Expected sale price using `max` with custom key
    expected_sale_price = max(Price_Exposure, key = sale_price)
    key, (bprice, cprice), (risk, shares) =  expected_sale_price
    #The best stock is the key in the expected_sale_Price
    return "Stock {} with values bprice={}, cprice = {}, risk={} and shares={} has the highest expected sale value".format(key, bprice, cprice, risk, shares)