CODEWITHSUNDEEP
python-2.7dictionary
Shady_94
Shady_94

Reputation: 47

How to create a new dictionary, that has the values of one dictionary as keys and the values of another dictionary as values

I have two dictionaries. In reality they are much longer. First:

Data = { "AT" : [1,2,3,4], "BE" : [ 4,2,1,6], "DE" : [ 5,7,8,9] }

2nd dict:

Data2 = { "AT" : ["AT1","AT2","AT3"], "BE" : ["BE1","BE2","BE3"], "DE" : ["DE1","DE2","DE3","DE4","DE5"] }

I now want a dictionary that assigns the values of the first to the values of the 2nd dictionary (the values of the 2nd dictionary are the new keys.)

Something like:

Result = { "AT1" : [1,2,3,4], "AT2" : [1,2,3,4], "AT3" : [1,2,3,4], "BE1" : [4,2,1,6], "BE2" : [4,2,1,6] and so on... }

I tried:

search= {k : v for k, v in Data.itervalues()}
result = {search[v]: k for v in Data2.itervalues() for k in Data.itervalues()}
print(result)

I get a too many values to unpack error and despite that im not quite sure if this does what i want it to do :/

Error:

Traceback (most recent call last):

  File "<ipython-input-18-e4ca3008cc18>", line 17, in <module>
    search= {k : v for k, v in Data.itervalues()}

  File "<ipython-input-18-e4ca3008cc18>", line 17, in <dictcomp>
    search= {k : v for k, v in Data.itervalues()}

ValueError: too many values to unpack

Thanks for any help in advance.

Upvotes: 1

Views: 49

Answers (2)

vlemaistre
vlemaistre

Reputation: 3331

Here is a way to do it using a dictionary comprehension :

result = {y : Data[x] for x in Data2 for y in Data2[x]}

Output :

{'AT1': [1, 2, 3, 4],
 'AT2': [1, 2, 3, 4],
 'AT3': [1, 2, 3, 4],
 'BE1': [4, 2, 1, 6],
 'BE2': [4, 2, 1, 6],
 'BE3': [4, 2, 1, 6],
 'DE1': [5, 7, 8, 9],
 'DE2': [5, 7, 8, 9],
 'DE3': [5, 7, 8, 9],
 'DE4': [5, 7, 8, 9],
 'DE5': [5, 7, 8, 9]}

Upvotes: 3

Vim
Vim

Reputation: 578

Way without using comprehension.

result = {}
for k,v in Data2.items():
    for _v in v:
        result[_v]=Data[k]
print(result)

Upvotes: 0

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