Comparing values of two dicts in Python

Question

I have 2 dictionaries:

budgets = {'Engineering': 4500.0,
 'Marketing': 5000.0,
 'Operations': 3000.0,
 'Sales': 2000.0}

spending = {'Engineering': 5020.0,
 'Marketing': 1550.0,
 'Operations': 3670.0,
 'Sales': 3320.0}

I'm trying to loop through them each and find out which values in spending are greater than the values in budgets. I currently have written:

for value in spending.values():
    if value in spending.values() > budgets.values():
        print 'Over Budget'
    else:
        print 'Under Budget'

However when I run this, they all print Over Budget which clearly isn't the case. Can someone please explain my error in approaching this?

Thanks :)

Answer 1

The section value in spending.values() > budgets.values() actually evaluates the boolean query value in spending.values()--a membership check--then compares the result of that to budget.values(): the values from budget. In Python, everything can be compared, so you compare the boolean to the list--the same thing every time, which in your case evaluates to True. What you'd want is more like this:

for key in spending:
    if spending[key] > budgets[key]:
        print('Over Budget')
    else:
        print('Under Budget')

EDIT: This pertains to Python 2 only. In Python 3, you get TypeError: unorderable types, which keeps you safe from mistakes like this.