concatenating arrays in python like matlab without knowing the size of the output array

I am trying to concatenate arrays in python similar to matlab

array1= zeros(3,500);
array=[array1, array2];

I did the following in python:

array=numpy.concatenate((array1, array2), axis=2)

however this gives me different results when i access try to “array[0,:]”
is there a way in python to put arrays in one array similar to matlab.

Thank you

Best answer

concatenate((a,b),1) or
hstack((a,b)) or
column_stack((a,b)) or

From here: