Introduction to Python List Sort

Introduction

Let's briefly understand what Python List Sort is before we dive deep into it.

Python List Sort is a built-in function in Python that arranges the elements of a list in a specific order. Sorting a list enables efficient searching and organizing of data.

With Python's List Sort, you can sort a list in ascending or descending order based on various criteria, such as numerical or alphabetical values.

This powerful feature simplifies data manipulation and analysis, making it an essential tool for developers and data scientists. Whether you need to sort a list of numbers, strings, or complex objects, Python List Sort provides a versatile solution to streamline your programming tasks.

In this tutorial, we will discuss how to sort lists in Python. We will also address a few FAQs on Python List Sort.

Advantages of Python List Sort

1. Efficient Sorting: Python List Sort provides a fast and efficient way to sort list elements, making data manipulation and analysis more convenient.
2. Versatility: It can sort various data types, including numbers, strings, and complex objects.
3. Ease of Use: The built-in function is easy to implement, requiring minimal code to achieve desired sorting outcomes.
4. Customizable Sorting: Python List Sort allows customization based on specific criteria, such as ascending or descending order, or by defining custom comparison functions.
5. Streamlined Programming: With Python List Sort, developers, and data scientists can easily organize and search through data, improving overall code efficiency and readability.

Python sort() and sorted()

Using the built-in list.sort() method or the built-in sorted() function, you can sort a list in Python.

While the list.sort() method sorts the list as it is, the sorted() function creates a new sorted list. Use the sorted() function to maintain the unsorted list if you want to. The fact that the sorted() function operates on any iterable object is another distinction.

The following is the syntax for both sort() and sorted():

list.sort(key=function, reverse=Boolean)

sorted(iterable, key=function, reverse=Boolean)

The following is the meaning of the optional keyword parameters key and reverse:

• key is a function that modifies one argument before a comparison. One value, which is utilized for the sort comparison, must be returned by the function.
• Reverse can either have a True or a False value. True is the default value. The list is arranged in reverse order when this argument is set to false.

The “less than” (<) operator is used to compare list items, and the elements are then sorted ascending. If you have a list that contains both strings and integers, the sort operation will not succeed, since the operator does not permit comparing a string to an integer.

The example that follows demonstrates how to alphabetically order a list of strings:

directions = ["north", "east", "south", "west"] 

directions.sort()

print('Sorted list:', directions)

Sorted list: ['east', 'north', 'south', 'west']

Use the sorted() function to keep the original list unchanged:

directions = ["north", "east", "south", "west"] 

sorted_directions = sorted(directions)

print('Sorted list:', sorted_directions)

Sorted list: ['east', 'north', 'south', 'west']

Set the reverse argument to True to sort the list in reverse (descending) order:

directions = ["north", "east", "south", "west"] 

directions.sort(reverse=True)

print('Sorted list:', directions)

Output

Sorted list: ['west', 'south', 'north', 'east']

Sorting with Function

More complicated sorting processes can be carried out thanks to the key argument, which accepts a function.

Organizing the elements by length would be the most straightforward example:

directions = ["Arya", "Daenerys", "Jon", "Brienne"] 

directions.sort(key=len)

print('Sorted list:', directions)

The len() function is used to return the string's character count, which is then used as a comparator:

Output

Sorted list: ['Jon', 'Arya', 'Brienne', 'Daenerys']

Additionally, you can develop a unique function and utilize it as the primary parameter for comparison. Here is an illustration of how to arrange a list of integers according to the sum of their digits:

def sum_digits(num): 
    digits = [int(x) for x in str(num)] 
    return sum(digits) 

numbers = [23, 77, 19, 310, 219] 

numbers.sort(reverse=True, key=sum_digits)

print('Sorted list:', numbers)

Output

Sorted list: [77, 219, 19, 23, 310]

Another example would be to sort a complex list, such as a list of tuples, using the key argument:

numbers = [(3, 14), (1, 61), (2, 71)]

numbers.sort(key=lambda k: k[0])

print('Sorted list:', numbers)

The anonymous (lambda) function we're employing returns the tuple's first element. The value that the function returned is used to order the list:

Output

Sorted list: [(1, 61), (2, 71), (3, 14)]

It is possible to order a list of dictionaries using the same method:

elements = [
    {'name': 'Germanium', 'number': 25, 'symbol': 'ge'},
    {'name': 'Silver', 'number': 47, 'symbol': 'ag'},
    {'name': 'Iron', 'number': 26, 'symbol': 'fe'},
]

elements.sort(key=lambda k: k['name'])

print('Sorted list:', elements)

The value of the name key, which is utilized for comparison, is returned by the lambda function:

Output

Sorted list: [
    {'name': 'Germanium', 'number': 25, 'symbol': 'ge'}, 
    {'name': 'Iron', 'number': 26, 'symbol': 'fe'}, 
    {'name': 'Silver', 'number': 47, 'symbol': 'ag'}
]

Use the Operator module functions to sort a complex function more effectively and quickly. As an illustration:

from operator import itemgetter

elements = [
    {'name': 'Germanium', 'number': 25, 'symbol': 'ge'},
    {'name': 'Silver', 'number': 47, 'symbol': 'ag'},
    {'name': 'Iron', 'number': 26, 'symbol': 'fe'},
]

elements.sort(key=itemgetter('symbol'))

print('Sorted list:', elements)

The key symbol value is retrieved using the itemgetter function:

Output

Sorted list: [
    {'name': 'Silver', 'number': 47, 'symbol': 'ag'},
    {'name': 'Iron', 'number': 26, 'symbol': 'fe'},
    {'name': 'Germanium', 'number': 25, 'symbol': 'ge'}
]

FAQs About Python List Sort

Conclusion

We hope this detailed tutorial helped you learn about sort() method and the sorted() function, we demonstrated.

If you have any queries, please leave a comment below and we’ll be happy to respond to them.