When you try to transpose a 1D array, it does nothing. This is the correct behavior, since it transposing a 1D array is meaningless. However, this can often lead to unexpected errors since this is rarely what you want. You can convert the array to 2D, using np.atleast_2d or arr[None], but this makes simple linear algebra computations more difficult.

I propose adding an argument to transpose, perhaps called expand or expanddim, which if True (it is False by default) will force the array to be at least 2D. A shortcut property, ndarray.T2, would be the same as ndarray.transpose(True).