Reputation: 195
I want to produce a 3-dimensional numpy.ndarray from a multi-indexed pandas.DataFrame. More precisely, say I have:
df = pd.DataFrame([[1, '1' , 1, 10], [1, '2', 2, 20], [2, '1', 5, 30]], columns=['x', 'y', 'z', 't'])
df = df.set_index(['x','y'])
df
which gives me
z t
x y
1 1 1 10
2 2 20
2 1 5 30
and I want to write a function which returns, with the above argument, the numpy.ndarray
[[[1, 10],
[2, 20]],
[[5, 30],
[NaN, NaN]]]
Pandas multi-index looks like a substitute for multidimensional arrays, but it does not provide (or at least does not document) ways to go back and forth...
Thanks.
Upvotes: 0
Views: 85
Reputation: 4343
Use:
df.to_xarray().to_array().values.transpose(1,2,0)
>>[[[ 1. 10.]
[ 2. 20.]]
[[ 5. 30.]
[nan nan]]]
Upvotes: 1