How do I scale down integers from multiple values in a dictionary?

Question

I want to write a function that will operate on multiple dictionary values at once.

Specifically, I want to take the all the values of selected_keys, divide them by 1 million, and round to two decimal places. Something like this:

def scale_down_movie(movie):
    selected_keys = movie['budget'], movie['budget_2013$'], movie['domgross'], movie['domgross_2013$'], movie['intgross'], movie['intgross_2013$']
    for value in selected_keys: 
        round(value/1000000, 2)   
    return movie

scale_down_movie(movies[0]) is currently outputting:

{'budget': 13000000,
 'domgross': 25682380.0,
 'intgross': 42195766.0,
 'budget_2013$': 13000000,
 'domgross_2013$': 25682380.0,
 'intgross_2013$': 42195766.0
}

desired output:

{'budget': 13.00,
 'domgross': 25.68,
 'intgross': 42.19,
 'budget_2013$': 13.00,
 'domgross_2013$': 25.68,
 'intgross_2013$': 42.19
}

Thank you.

UPDATE:

Used this code:

def scale_down_movie(movie):
    selected_keys = ('domgross_2013$', 'budget', 'budget_2013$', 'domgross', 'domgross_2013$', 'intgross', 'intgross_2013$')
    for key in selected_keys:
        movie[key] = round(movie[key]/1000000, 2)  
    return movie

Getting unexpected results.

Expected output:

scale_down_movie(parsed_movies[9])

{'binary': 'FAIL',
'budget': 130.0,
'budget_2013$': 130.0,
'clean_test': 'notalk',
'code': '2013FAIL',
'decade code': 1.0,
'domgross': 60.52,
'domgross_2013$': 60.52,
'imdb': 'tt1815862',
'intgross': 244.37,
'intgross_2013$': 244.37,
'period code': 1.0,
'test': 'notalk',
'title': 'After Earth',
'year': 2013}

Actual output:

{'year': 2013,
 'imdb': 'tt1815862',
 'title': 'After Earth',
 'test': 'notalk',
 'clean_test': 'notalk',
 'binary': 'FAIL',
 'budget': 0.0,
 'domgross': 0.0,
 'intgross': 0.0,
 'code': '2013FAIL',
 'budget_2013$': 0.0,
 'domgross_2013$': 0.0,
 'intgross_2013$': 0.0,
 'period code': 1.0,
 'decade code': 1.0}

SOLUTION:

def scale_down_movie(movie):
    scaled_movie = movie.copy()
    selected_keys = ('domgross_2013$', 'budget', 'budget_2013$', 'domgross', 'domgross_2013$', 'intgross', 'intgross_2013$')
    for key in selected_keys: 
        scaled_movie[key] = round(scaled_movie[key]/1000000, 2)   
    return scaled_movie

WHAT WENT WRONG: Every time you push run, it divides by a million again, so it quickly approaches 0.

HOW TO FIX IT: Use .copy() so that you're not changing the original.

Answer 1

How about something like:

def scale_down_movie(movie):
selected_keys = ('domgross_2013$', 'budget', 'budget_2013$', 'domgross', 'domgross_2013$', 'intgross', 'intgross_2013$')
for key in selected_keys: 
    movie[key] = round(movie[key]/1000000, 2)   
return movie

However this may not return the values you're expecting as you are doing integer division. If you replace movie[key]/1000000 with movie[key]/float(1000000) it should work as expected.

Answer 2

If you need a new dictionary

def scale_down_movie(movie):
    selected_keys = {'domgross_2013$', 'budget', 
'budget_2013$', movie'domgross', 'domgross_2013$', 
'intgross', 'intgross_2013$'}

    return { k: v/1000000., 2)  for k, v in selected_keys.items if k in selected_keys}

Answer 3

You're returning the wrong value:

def scale_down_movie(movie):
    selected_keys = movie['domgross_2013$'], movie['budget'], 
movie['budget_2013$'], movie['domgross'], movie['domgross_2013$'], 
movie['intgross'], movie['intgross_2013$']
    for value in selected_keys: 
        round(value/1000000, 2)   
    return selected_keys