[Python] Concatenating empty array in Numpy

in Matlab I do this:

>> E = [];
>> A = [1 2 3 4 5; 10 20 30 40 50];
>> E = [E ; A]

E =

1 2 3 4 5
10 20 30 40 50


Now I want the same thing in Numpy but I have problems, look at this:

>>> E = array([],dtype=int)
>>> E
array([], dtype=int64)
>>> A = array([[1,2,3,4,5],[10,20,30,40,50]])

>>> E = vstack((E,A))
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/numpy/core/shape_base.py", line 226, in vstack
return _nx.concatenate(map(atleast_2d,tup),0)
ValueError: array dimensions must agree except for d_0


I have a similar situation when I do this with:

>>> E = concatenate((E,A),axis=0)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: arrays must have same number of dimensions


Or:

>>> E = append([E],[A],axis=0)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/numpy/lib/function_base.py", line 3577, in append
return concatenate((arr, values), axis=axis)
ValueError: arrays must have same number of dimensions

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