Finding the mean across rows 

Find the mean across rows (that is, reduce columns) with this:

tf.reduce_mean(input_tensor=numbers, axis=1) # [ (4. + 5. )/2 , (7. + 3. )/2] = [4.5, 5]

The output will be as follows:

<tf.Tensor: id=64, shape=(2,), dtype=float32, numpy=array([4.5, 5. ], dtype=float32)>

When keepdims is True, the reduced axis is retained with a length of 1:

tf.reduce_mean(input_tensor=numbers, axis=1, keepdims=True)

The output is as follows:

([[4.5], [5]])      (2 rows, 1 column)