merging dictionaries

[v13tn1g]

so basically i've written most of the code the only problem that i'm having is that the output that it gives me will not return a key with a different type. It will either return me keys with only int, or only str..for example

def merge_dictionaries(d1, d2):
    '''Return a dictionary that is the result of merging the two given 
    dictionaries. In the new dictionary, the values should be lists. If a key 
    is in both of the given dictionaries, the value in the new dictionary should
    contain both of the values from the given dictionaries, even if they are the 
    same. '''
    
    d3 = {}
    for c in d1:
        if c in d2:
            d3[c] = [d1[c], d2[c]]
        else:
            d3[c] = [d1[c]]
    print d3

how i tested it is with:

merge_dictionaries({ 1 : 'a', 2 : 9, -8 : 'w'}, {2 : 7, 'x' : 3, 1 : 'a'})

and the out put is:

{-8: ['w'], 1: ['a', 'a'], 2: [9, 7]}

why doesn't it print out the 'x' key and value??

[bvdet]

Because d2 has a key that d1 does not have. You only iterate on d1, so key 'x' is never seen.

-BV

[bvdet]

Take a look at this:

import copy

def merge_dictionaries(d1, d2):
    d3 = copy.copy(d1)
    for key in d2:
        if key in d3:
            d3[key] = [d3[key], d2[key]]
        else:
            d3[key] = [d2[key]]
    return d3

dd1 = { 1 : 'a', 2 : 9, -8 : 'w'}
dd2 = {2 : 7, 'x' : 3, 1 : 'a'}
print merge_dictionaries(dd1, dd2)

[v13tn1g]

in this case you imported copy, what is that?

[bvdet]

in this case you imported copy, what is that?

copy.copy makes a shallow copy of an object. From Python documentation:
"A shallow copy constructs a new compound object and then (to the extent possible) inserts references into it to the objects found in the original."

This will do the same thing:

d3 = dict(d1.items())