python - Work out correct money denominations for change -

working on django project. on payment model have simple def save

def save(self, *args, **kwargs):     self.amount_change = self.amount_due - self.amount_paid     return super(payment, self).save(*args, **kwargs) 

if amount_change comes -455.50 i'd return change as

• 2x200
• 1x50
• 1x5
• 1x0.5

what i'd breakdown amount_change money denominations have , return change client correct notes , or coins. denominations [200, 100, 50, 20, 10, 5, 1, 0.5]

how go doing this? appreciated.

building upon this answer, believe returning desired results:

from collections import counter  def change(amount):     money = ()      coin in [200, 100, 50, 20, 10, 5, 1, 0.5]:         num = int(amount/coin)         money += (coin,) * num         amount -= coin * num      return counter(money) 

input , output:

>>> c = change(455.50) >>> print c counter({200: 2, 0.5: 1, 50: 1, 5: 1}) 

edit: if need pass in negative number, create new variable inside function multiplying -1 , use inside function instead of amount