pythondictionarypandasdataframe

How to create a dictionary of two pandas DataFrame columns


What is the most efficient way to organise the following pandas Dataframe:

data =

Position    Letter
1           a
2           b
3           c
4           d
5           e

into a dictionary like alphabet[1 : 'a', 2 : 'b', 3 : 'c', 4 : 'd', 5 : 'e']?


Solution

  • In [9]: pd.Series(df.Letter.values,index=df.Position).to_dict()
    Out[9]: {1: 'a', 2: 'b', 3: 'c', 4: 'd', 5: 'e'}
    

    Speed comparion (using Wouter's method)

    In [6]: df = pd.DataFrame(randint(0,10,10000).reshape(5000,2),columns=list('AB'))
    
    In [7]: %timeit dict(zip(df.A,df.B))
    1000 loops, best of 3: 1.27 ms per loop
    
    In [8]: %timeit pd.Series(df.A.values,index=df.B).to_dict()
    1000 loops, best of 3: 987 us per loop