How to sort arrays in NumPy

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In the previous article, we saw how we could search for arrays in NumPy using different functions. In this article of today, we are going to see how we can sort different elements in input array by using different built-in functions in NumPy.

To begin with sorting refers means arranging elements in an orderly manner such as alphabetically, numerically, ascending and many more.

Using sort () functions

This is a built-in function in NumPy that returns a copy of the sorted array in order. This array is arranged in sorted format.

Example 

import numpy as np
arr = np.array(['e', 'b', 'a', 'c'])
print(np.sort(arr))

NumPy passes the command to the sort function which instructs the compiler to arrange the alphabets in order.

OUTPUT

Using np.argsort()

This function is used when we want the indices of the array, after when it has been sorted. 

Example

import numpy as np
arr = np.array([[6,1,3,8,12,2]])
print(np.argsort(arr))

OUTPUT

In the table below, is a list functions with their uses we can use to sort out different arrays.

Functions	When to use them
np.ndarraysort()	Use to sort arrays in order
np.msort()	Returns arrays that are sorted along the first axis
np.partition()	Divides the array sorted into smaller arrays or partition
np.argpartition(	It returns the specified array after it has been partition
np.sort_compex()	It sorts out the real and imaginary parts of an array

Arrays of different data-types can be sorted using the sort() functions

Example

Sorting the array of a Boolean expressions

import numpy as np
arr = np.array([True, False, True])
print(np.sort(arr))

NumPy passes the command to the function, which then tells the compiler to sort out given expression.

OUTPUT

Sorting out 2-D array

When the sort function is used on 2-D array, both the arrays in the given 2-D are sorted

Example

import numpy as np
arr = np.array([['a', 'm', 'd'], ['z', 'f', 'j']])
print(np.sort(arr))

Just like in the example above, the functions are being sorted by the compiler, but in this case the two given arrays are sorted simultaneously.

OUTPUT

There are many other functions used in sorting that were not mention in this article. Sorting is very important in arranging data in a particular order. Hope this article was very interesting. Have a nice day coding.