how to indexing pandas dataframe with index list?

Question

I have a dataframe like the belows.

And I have a list like belows.

a
[['w', 'x', 'w'], 
['x', 'y', 'y']]

How can I get the results like

[[5,7,3],
[4,2,5]]

If the only way is using a for loop, which is the fastest way?

BENY · Accepted Answer · 2018-08-27 02:41:29Z

4

I think for loop should be fast enough

[[df.loc[z,y] for z,y in zip(x,df.columns)] for x in l ]
Out[981]: [[5, 7, 3], [4, 2, 5]]

answered Aug 27, 2018 at 2:41

BENY

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2 Comments

df.at instead.

Thank u so much. I use the df.at version.

piRSquared · Accepted Answer · 2018-08-27 03:22:12Z

2

Assuming length of sub-lists are always the same as the length of columns

[[*df.lookup(i, df.columns)] for i in a]

[[5, 7, 3], [4, 2, 5]]

answered Aug 27, 2018 at 3:22

piRSquared

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Thanks a lot. df.at is definitely faster than df.loc