from typing import Dict

MAX_FOR_EXPRESS_CHECKOUT = 8

def express_checkout(product_to_quantity: Dict[str, int]) -> bool:
    """Return True iff the grocery order in product_to_quantity qualifies for the
    express checkout. product_to_quantity maps products to the numbers of those
    items in the grocery order.
    
    >>> express_checkout({'banana': 3, 'soy milk': 1, 'peanut butter': 1})
    True
    >>> express_checkout({'banana': 3, 'soy milk': 1, 'twinkie': 5})
    False
    """
    
    total = 0
    
    # iterating over indices doesn't help us with dictionaries
    # because the keys are not ordered numbers
    #for i in range(len(product_to_quantity)):
    
    # loop over the keys
    for product in product_to_quantity:
        total = total + product_to_quantity[product]
        
    return total <= MAX_FOR_EXPRESS_CHECKOUT