how to convert 2d list to 2d numpy array?

Question

I have a 2D list something like

a = [[1, 2, 3], [4, 5, 6], [7, 8, 9]] 

and I want to convert it to a 2d numpy array. Can we do it without

Answer 1

np.array() is even more powerful than what unutbu said above. You also could use it to convert a list of np arrays to a higher dimention array, the following is a simple example:

aArray=np.array([1,1,1])

bArray=np.array([2,2,2])

aList=[aArray, bArray]

xArray=np.array(aList)

xArray's shape is (2,3), it's a standard np array. This operation avoids a loop programming.