replace each column of pandas dataframe with each value of array

Question

df is like this,

     A    B    C
0  NaN  150 -150
1  100  NaN  150
2 -100 -150  NaN
3 -100 -150  NaN
4  NaN  150  150
5  100  NaN -150

Another array is array([1, 2, 3])

I want to replace non-null value in each column with each value in array, and the result will be,

      A     B     C
0   NaN   2     3
1   1     NaN   3
2   1     2     NaN
3   1     2     NaN
4   NaN   2     3
5   1     NaN   3

How can I achieve this in a simple way? I write something like,

df[df.notnull()] = np.array([1,2,3])
df[df.notnull()].loc[:,] = np.array([1,2,3])

but all cannot work.

DSM · Accepted Answer · 2015-12-10 17:11:33Z

1

How about:

>>> (df * 0 + 1) * arr
    A   B   C
0 NaN   2   3
1   1 NaN   3
2   1   2 NaN
3   1   2 NaN
4 NaN   2   3
5   1 NaN   3

answered Dec 10, 2015 at 17:11

DSM

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