pythonpandasdataframe

Convert pandas series of lists to dataframe


I have a series made of lists

import pandas as pd
s = pd.Series([[1, 2, 3], [4, 5, 6]])

and I want a DataFrame with each column a list.

None of from_items, from_records, DataFrame Series.to_frame seem to work.

How to do this?


Solution

  • As @Hatshepsut pointed out in the comments, from_items is deprecated as of version 0.23. The link suggests to use from_dict instead, so the old answer can be modified to:

    pd.DataFrame.from_dict(dict(zip(s.index, s.values)))
    

    --------------------------------------------------OLD ANSWER-------------------------------------------------------------

    You can use from_items like this (assuming that your lists are of the same length):

    pd.DataFrame.from_items(zip(s.index, s.values))
    
       0  1
    0  1  4
    1  2  5
    2  3  6
    

    or

    pd.DataFrame.from_items(zip(s.index, s.values)).T
    
       0  1  2
    0  1  2  3
    1  4  5  6
    

    depending on your desired output.

    This can be much faster than using an apply (as used in @Wen's answer which, however, does also work for lists of different length):

    %timeit pd.DataFrame.from_items(zip(s.index, s.values))
    1000 loops, best of 3: 669 µs per loop
    
    %timeit s.apply(lambda x:pd.Series(x)).T
    1000 loops, best of 3: 1.37 ms per loop
    

    and

    %timeit pd.DataFrame.from_items(zip(s.index, s.values)).T
    1000 loops, best of 3: 919 µs per loop
    
    %timeit s.apply(lambda x:pd.Series(x))
    1000 loops, best of 3: 1.26 ms per loop
    

    Also @Hatshepsut's answer is quite fast (also works for lists of different length):

    %timeit pd.DataFrame(item for item in s)
    1000 loops, best of 3: 636 µs per loop
    

    and

    %timeit pd.DataFrame(item for item in s).T
    1000 loops, best of 3: 884 µs per loop
    

    Fastest solution seems to be @Abdou's answer (tested for Python 2; also works for lists of different length; use itertools.zip_longest in Python 3.6+):

    %timeit pd.DataFrame.from_records(izip_longest(*s.values))
    1000 loops, best of 3: 529 µs per loop
    

    An additional option:

    pd.DataFrame(dict(zip(s.index, s.values)))
    
       0  1
    0  1  4
    1  2  5
    2  3  6