Mastering pandas - Second Edition

Array sorting

Arrays can be sorted in various ways:

1. Sorting the array along an axis; first, let's discuss this along the y axis:

    In [43]: ar=np.array([[3,2],[10,-1]])
                 ar
    Out[43]: array([[ 3,  2],
                    [10, -1]])
    In [44]: ar.sort(axis=1)
                 ar
    Out[44]: array([[ 2,  3],
                    [-1, 10]])

2. Here, we will explain the sorting along the x axis:

    In [45]: ar=np.array([[3,2],[10,-1]])
                 ar
    Out[45]: array([[ 3,  2],
                    [10, -1]])
    In [46]: ar.sort(axis=0)
                 ar
    Out[46]: array([[ 3, -1],
                    [10,  2]])  

3. Sorting by in-place (np.array.sort) and out-of-place (np.sort) functions.
4. Other operations that are available for array sorting include the following:

• np.min(): This returns the minimum element in the array
• np.max(): This returns the maximum element in the array
• np.std():