CODEWITHSUNDEEP
python-3.xpandasdictionarytuples
RustyShackleford
RustyShackleford

Reputation: 3667

How to zip multiple columns between two dataframes into a dictionary object?

I have two dataframes like so:

df1

colA  colB  
1      3
2      4

df2

colA  colB  
A      C
B      D

I want to create a dictionary object that will allow me to map new values from df1 and convert them to values for df2.

I am able to create the dictionary object between columns like so:

dict(zip(df1.colA.unique(),df2.colA.unique()))

This gives me the output:

{1:'A',2:'B'}

how do I do this for multiple columns to create a single large dictionary that will be used for converting new data?

I tried adding multiple columns like this:

dict(zip(df1.A.unique(),df2.A.unique(),df1.B.unique(),df2.B.unique()))

I get error:

ValueError: dictionary update sequence element #0 has length 4; 2 is required

Upvotes: 2

Views: 1513

Answers (1)

anky
anky

Reputation: 75080

A dictionary can only have 1 key and 1 value, when you zip multiple columns like that, you are asking python 2 create more than 2 sequence element which isnt possible. You can instead create the first dict and update it with another like:

d=dict(zip(df1.colA.unique(),df2.colA.unique()))
d.update(dict(zip(df1.colB.unique(),df2.colB.unique())))
print(d)

{1: 'A', 2: 'B', 3: 'C', 4: 'D'}

Upvotes: 1

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