The argsort() function in the numpy module (turn)

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The argsort function is a function in the Numpy module:

>>> import numpy
>>> help(numpy.argsort)
Help on function argsort in module numpy.core.fromnumeric:

argsort(a, axis=-1, kind='quicksort', order=None)
Returns the indices that would sort an array.

The AN Along the INDIRECT Sort the Perform GIVEN the using Axis The algorithm specified
by The keyword `kind`. It AN Array Returns indices of Shape of The Same AS
` a` The GIVEN that Along Axis Data index in the sorted Order.

  It can be seen argsort function Returns the index value of the array value from small to large

Examples：

One dimensional array: One dimensional array

>>> x = np.array([3, 1, 2])
>>> np.argsort(x)
array([1, 2, 0])

Two-dimensional array:二维数组

>>> x = np.array([[0, 3], [2, 2]])
>>> x
array([[0, 3],
[2, 2]])

>>> np.argsort(x, axis=0) #sort by column
array([[0, 1],
[1, 0]])

>>> np.argsort(x, axis=1) #Sort by row
array([[0, 1],
[0, 1]])

Examples:

>>> x = np.array([3, 1, 2])
>>> np.argsort(x) #Arrange in ascending order
array([1, 2, 0])
>>> np.argsort(-x) #Arrange in descending order
array([0, 2, 1])

>>> x[np.argsort(x)] #Array sorted by index value
array([1, 2, 3])
>>> x[np.argsort(-x)]
array([3, 2, 1])

Another way to sort in descending order:

>>> a = x[np.argsort(x)]
>>> a
array([1, 2, 3])
>>> a[::-1]
array([3, 2, 1])