Question

Change Calculator

Task:

Create a program that will input a price and a money amount. The program will then decide if there is any change due and calculate how much change and which coins to hand out. Coins will be preferred in the least number of coins (starting with quarters and working your way down to pennies).

Input:

total_price, amount_tender
allow the user to input 'q' for either value if they want to quit the program

Validate:

total_price

• cannot be negative
• cannot be 0
• cannot be text (other than q for quit)

amount_tender

• cannot be less than total_price
• can be equal to total_price
• cannot be text (other than q for quit)

Output:

change_amount
number_quarters
number_dimes
number_nickels
number_pennies

IF any of these values is zero, DO NOT output that value. IE: if the change is 26 cents you only need to tell the user they will receive 1 quarter and 1 penny. No more, no less.

Hint:

Use modular division to track the remainder after calculating each number of coins.

Convert the decimal to a whole number to make the calculation easier. Use math.floor() to round DOWN to the nearest integer.

Use a try-catch (try-except) to help validate input. Try to set the input value into afloat and if it does not fit then you can test the input further without an error stopping your program.

Requirements:

Use a function

Use a loop

Validate all input

Use an IF statement

Use helpful, human-readable text both to prompt for input, but also to let the user know about invalid inputs. Simply stating it is invalid doesn't help the user to correct their error.

If you can make your program also calculate the number of dollars for change. That is, change above 99 cents.

Turn IN:

Python file ONLY

Answer 1

In case of any queries,please comment. I would be very happy to assist all your queries.Please give a Thumps up if you like the answer.

Program

import sys
def calcCoins(moneyback):
quarter = 0.25
dime = 0.10
nickel = 0.05
penny = 0.01

moneybacknew=moneyback-int(moneyback)
quarter_money_back = int(moneybacknew / quarter)

partialtotal = moneybacknew - quarter_money_back * quarter
dimes_money_back = int(partialtotal / dime)
dpartialtotal = partialtotal - dimes_money_back * dime

nickel_money_back = int(dpartialtotal / nickel)
npartialtotal = dpartialtotal - nickel_money_back * nickel

penny_money_back = int(npartialtotal / penny)
penny_partial_total = npartialtotal - penny_money_back * penny

return quarter_money_back,dimes_money_back,nickel_money_back,penny_money_back

def calcDollar(moneyback):
hundred_dollar_bill = 100
fifty_dollar_bill = 50
twenty_dollar_bill = 20
ten_dollar_bill = 10
five_dollar_bill = 5
two_dollar_bill = 100
one_dollar_bill = 1

fiftydmb = int(moneyback / fifty_dollar_bill)
fiftydnewbalance=moneyback-fiftydmb*fifty_dollar_bill

twentydmb=int(fiftydnewbalance / twenty_dollar_bill)
twentydnewbalance=fiftydnewbalance-twentydmb*twenty_dollar_bill

tendmb=int(twentydnewbalance / ten_dollar_bill)
tendnewbalance=twentydnewbalance-tendmb*ten_dollar_bill

fivedmb=int(tendnewbalance / five_dollar_bill)
fivednewbalance=tendnewbalance-fivedmb*five_dollar_bill

twodmb= int(fivednewbalance / two_dollar_bill)
twodnewbalance=fivednewbalance-twodmb*two_dollar_bill

onedmb=int(twodnewbalance / one_dollar_bill)
onednewbalance=twodnewbalance-onedmb*one_dollar_bill

return fiftydmb,twentydmb,tendmb,fivedmb,twodmb,onedmb

def main():
while True:
try:
total_price = input("Enter the price of item: $ ")

if (str(total_price)=='q'):#user want to quit the program
print("Quit!!!")
sys.exit(0)
total_price=float(total_price)
if (total_price<=0):#total_price cannot be negative and cannot be 0
print("Sorry, Total price must not be negative or zero.")
continue
  
except ValueError:
print("Sorry, Enter valid amount")
continue
else:
break

while True:
try:
amount_tender = input("Enter how much money given: $")
if (str(amount_tender)=='q'):#user want to quit the program
print("Quit!!!")
sys.exit(0)
amount_tender=float(amount_tender)
if (amount_tender<=total_price):#amount_tender cannot be less than total_price or can be equal to total_price
print("Sorry,Amount Tender cannot be less than or equal to Total Price")
continue
except ValueError:
print("Sorry, Enter valid amount")
continue

  
else:
break
  
change_amount = amount_tender - total_price

fiftydmb,twentydmb,tendmb,fivedmb,twodmb,onedmb=calcDollar(change_amount)
number_quarters,number_dimes,number_nickels,number_pennies=calcCoins(change_amount)
  
print("Change Due : $",change_amount)
print("Balance to be given : ")

if fiftydmb>0:
print (fiftydmb,"$ 50 Bill")
if twentydmb>0:
print (twentydmb,"$ 20 Bill")
if tendmb>0:
print (tendmb,"$ 10 Bill")
if fivedmb>0:
print (fivedmb,"$ 5 Bill")
if twodmb>0:
print (twodmb,"$ 2 Bill")
if onedmb>0:
print (onedmb,"$ 1 Bill")

if number_quarters>0:
print(number_quarters, 'quarters' )
if number_dimes>0:
print(number_dimes,'dime')
if number_nickels>0:
print(number_nickels,'nickels')
if number_pennies>0:
print(number_pennies, 'pennys')
main()

Output

Enter the price of item: $ q
Quit!!!
>>>

Enter the price of item: $ 0
Sorry, Total price must not be negative or zero.
Enter the price of item: $ -9
Sorry, Total price must not be negative or zero.
Enter the price of item: $ w
Sorry, Enter valid amount
Enter the price of item: $ q
Quit!!!
>>>

Enter the price of item: $ 9
Enter how much money given: $q
Quit!!!
>>>

Enter the price of item: $ 9
Enter how much money given: $9
Sorry,Amount Tender cannot be less than or equal to Total Price
Enter how much money given: $4
Sorry,Amount Tender cannot be less than or equal to Total Price
Enter how much money given: $100
Change Due : $ 91.0
Balance to be given :
1 $ 50 Bill
2 $ 20 Bill
1 $ 1 Bill

Enter the price of item: $ 0
Sorry, Total price must not be negative or zero.
Enter the price of item: $ -9
Sorry, Total price must not be negative or zero.
Enter the price of item: $ 9.74
Enter how much money given: $8
Sorry,Amount Tender cannot be less than or equal to Total Price
Enter how much money given: $0
Sorry,Amount Tender cannot be less than or equal to Total Price
Enter how much money given: $100
Change Due : $ 90.26
Balance to be given :
1 $ 50 Bill
2 $ 20 Bill
1 quarters
1 pennys

Program Screenshot