NumPy’s array class is called ndarray. The more important attributes of an ndarray object are:

• ndarray.ndim: the number of axes (dimensions) of the array.
• ndarray.shape: the dimensions of the array. This is a tuple of integers indicating the size of the array in each dimension. For a matrix with n rows and m columns, shape will be (n,m). The length of the shape tuple is therefore the number of axes, ndim.
• ndarray.size: the total number of elements of the array. This is equal to the product of the elements of shape.
• ndarray.dtype: an object describing the type of the elements in the array.