Errors saving stacked NumPy array to text

Question

I am combining column data from three different input arrays into a new csv. To do so I am using the NumPy stack function. Right now I have a [12,3] stacked NumPy array that I am trying to export to a csv.

VI_Samples_v4 = numpy.stack((samplename,sample_start_date,sample_type_code), axis =1)

When I use the numpy save text

numpy.savetxt('array.csv', [VI_Samples_v4], fmt='%s', delimiter=',')

I get this Error: "ValueError: Expected 1D or 2D array, got 3D array instead." I am fairly certain it is a 2D array. When I ask Numpy for the array shape, I get (12,3).

VI_Samples_v4.shape

What's my error, then?

Answer 1

The problem is the square brackets you've placed around your array in the call to numpy.savetxt . By passing a list containing your 2D array, you're causing numpy.savetxt to read it as a 3D array. Just pass the array without the square brackets like so:

numpy.savetxt('array.csv', VI_Samples_v4, fmt='%s', delimiter=',')