how can I flatten an 2d numpy array, which has different length in the second axis?

Question

I have a numpy array which looks like:

myArray = np.array([[1,2],[3]])

But I can not flatten it,

In: myArray.flatten()
Out:         


        

Answer 1

np.hstack works in this case

In [69]: np.hstack(myArray)
Out[69]: array([1, 2, 3])