找出python中的货币变化

Question

I have an assignment where I have to prompt the user for cost of a product and amount paid, I have to output change in pennies, dimes, quarters, $1, $5, $20, $50, and $100, for example: The cost of the item is $19.99 and the client pays with a $50 bill. The change to be provided is 1 $20 bill, one $10 bill, and one penny. I am confused how to get an output like that though, any help would be greatly appreciated, heres what I have so far

cost = float(input('Cost: '))
amount_paid = float(input('Amount paid: '))
penny = 0.01
dime = 0.10
quarter = 0.25
dollar_1 = 1.00
dollar_5 = 5.00
dollar_10 = 10.00
dollar_20 = 20.00
dollar_50 = 50.00
dollar_100 = 100.00
change = cost - amount_paid
if amount_paid < cost:
    print('Error')

I dont know what to do next

Answer 1

A common misstep here is to use floats. You should instead convert everything to the smallest whole unit (a cent) and use integer math. Floating point math is...fuzzy.

currencies = {"penny": 1,
              "nickel": 5,
              "dime": 10,
              "quarter": 25,
              "dollar": 1_00,
              "five": 5_00,
              "ten": 10_00,
              "twenty": 20_00,
              "fifty": 50_00,
              "hundred": 100_00}
# never seen that numeric notation before? It's safe to embed underscores
# in numerical literals! It's often used for large numbers in place of
# commas, but it makes sense here in place of a period.

Then you should only need to define a dictionary for the result, and use divmod to find how many of the denomination can fit in the amount left due.

change_due = {}

for denomination, amt in reversed(currencies.items()):
    if amt < amt_due:
        d, m = divmod(amt_due, amt)
        change_due[denomination] = d
        amt_due = m

Answer 2

welcome to stackoverflow! I wrote the code for you and this is how it works. Basically it sees each currency and uses integer division // to see how many integers can fit in. It then subtracts that amount from the remaining change and the process continues. Please ask if you don't understand something, or if you think there is an error. Code:

cost = float(input('Cost: '))
amount_paid = float(input('Amount paid: '))
penny = 0.01
dime = 0.10
quarter = 0.25
dollar_1 = 1.00
dollar_5 = 5.00
dollar_10 = 10.00
dollar_20 = 20.00
dollar_50 = 50.00
dollar_100 = 100.00
changeTypes = {dollar_100:0,dollar_50:0,dollar_20:0,dollar_10:0,dollar_5:0,dollar_1:0,quarter:0,dime:0,penny:0}
change = amount_paid-cost
if amount_paid < cost:
    print('Error: InsufficientFunds')
for changeType in changeTypes:
    numAmount = max(0,change//changeType)
    change-=numAmount*changeType
    changeTypes[changeType] = int(numAmount)


print(changeTypes)

PS you should make this a function, it shouldn't be too hard.

Answer 3

You could do this good with dictionaries, but without using still there are many ways to go about this, options are endless, heres one idea

def get_bills(change, value):
    if change//value > 0:
        bills = change//value
        change -= bills * value
        return bills, change
    else:
        return 0, change

cost = float(input('Cost: '))
paid = float(input('Amount Paid: '))
while paid < cost:
    paid = float(input('Amount Paid: '))

change = paid - cost

hundreds, change, = get_bills(change, 100)

fifties, change, = get_bills(change, 50)

twenties, change = get_bills(change, 20) 

tens, change = get_bills(change, 10) 

fives, change = get_bills(change, 5)

ones, change = get_bills(change, 1)

quarters, change = get_bills(change, .25)

dimes, change = get_bills(change, .1) 

nickels, change = get_bills(change, .05)

pennies = round(change * 100)

print(f"Hundreds: {hundreds}, Fifties: {fifties}, Twenties: {twenties}," +
      f" Tens: {tens}, Fives: {fives}, Ones: {ones}, Quarters: {quarters}," +  
      f" Dimes: {dimes}, Nickels: {nickels}, Pennies: " +
      f"{pennies}")

Answer 4

    bill = float(input())
paid = float(input())
Available = {100.0:0,50.0:0,20.0:0,10.0:0,5.0:0,1.0:0,0.25:0,0.10:0,0.01:0}
due = paid-bill
for change in sorted(Available,reverse = True):
    amt= max(0,due//change)
    due-=amt*change
    Available[change] = int(amt)
print(Available)

Answer 5

I know this is a late response but maybe it can help someone.

Below is a code for doing exactly what you want. The program iterates through the notes available from largest to smallest and calculates how many times the current note may be used to deduct from the remaining change to be given.

Finally returning a list containing the notes used to reach the sum required.

# Available notes for change
notes = [500, 200, 100, 50, 20, 10]


def change_notes(change, notes):
    notes_out = []
    for note in notes:
        print(f"current note is {note}")
        sleep(1)
        while change > 0 and note <= change:
            if change - note >= 0:
                change -= note
                notes_out.append(note)
                print(f"change is {change}")
                sleep(1)
        if change == 0:
            break
            

    return notes_out