Convert single df column to list of lists

Question

How can you convert a single df column to a list of lists? using the df below, how can you return X to a list of lists.

df = pd.DataFrame({ 'X' : [1,2,3,4,5,2,3,4,5,6], 'Y' : [11,12,13,14,15,11,12,13,14,15], }) l = df['X'].values.tolist() [1, 2, 3, 4, 5, 2, 3, 4, 5, 6]

Converting two columns is possible:

l = df.values.tolist() [[1, 11], [2, 12], [3, 13], [4, 14], [5, 15], [2, 11], [3, 12], [4, 13], [5, 14], [6, 15]]

But I just want X.

[[1], [2], [3], [4], [5], [2], [3], [4], [5], [6]]

I checked that @NatheerAlabsi. I've referenced the differences in the question — jonboy
– jonboy, Commented Nov 27, 2019 at 2:21
Don’t use .values. For the sake of curiosity, why do you need to do this? — AMC
– AMC, Commented Nov 27, 2019 at 5:31
Also, could you tell me if the solution I posted works correctly? I don’t have access to a computer right now, so I want to be entirely certain. — AMC
– AMC, Commented Nov 27, 2019 at 5:36
yep this works. I need it for a later function. Specifically, to iterate more efficiently. Did you down vote everyones post? — jonboy
– jonboy, Commented Nov 27, 2019 at 5:46

BENY · Accepted Answer · 2019-11-27 02:19:12Z

1

IIUC

df.X.values[:,None].tolist() Out[85]: [[1], [2], [3], [4], [5], [2], [3], [4], [5], [6]]

answered Nov 27, 2019 at 2:19

324k22 gold badges176 silver badges250 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

AMC · Accepted Answer · 2019-11-27 05:33:51Z

Some of these solutions seem overcomplicated. I believe this should do the job.

res_list = [[elem] for elem in df['X']]

oppressionslayer · Accepted Answer · 2019-11-27 02:14:12Z

0

Try this:

 df['X'].apply(lambda x: [x]).tolist()

output:

[[1], [2], [3], [4], [5], [2], [3], [4], [5], [6]]

answered Nov 27, 2019 at 2:14

7,2242 gold badges11 silver badges26 bronze badges

I’m pretty sure you could just do .map(list).tolist().

MoonMist · Accepted Answer · 2019-11-27 02:11:02Z

If you want this output

[[1], [2], [3], [4], [5], [2], [3], [4], [5], [6]]

when starting with the input: [1,2,3,4,5,2,3,4,5,6]

then this should work fine

l = [[i] for i in df['X'].values.tolist()]