A simple and flexible function in TensorFlow, to calculate the Euclidean distance between all row vectors in a tensor, the output is a 2D numpy array.
To clarify the fuction, we represent the input tensor as I with shape (n, m), and the output as O with shape (n, n), and i, j are both integer in the range 0~n.
O[i,j] is the Euclidean distance between i-th row and j-th row of I.