Have you ever encountered a circumstance where you needed to sort a list in Python but were unable to do it using the built-in ‘sort()’ function? Programmers frequently need to sort lists, and Python offers the sort()’ function as an easy and effective solution. However, there may be circumstances in which you are unable to use the ‘sort()’ function or simply want to investigate different options. This article will discuss various methods on How to Sort a List in Python Without the Sort Function, giving you the flexibility and knowledge to handle such situations.

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What is sort in Python?

The term “sort” in Python describes the procedure of putting things in a predetermined order. It is frequently used to arrange a group of objects, such as a list, in ascending or descending order according to a particular criterion.

Sorting operations can be carried out using built-in functions in Python. The most popular function is ‘sorted()’, which accepts an iterable as input and returns a new, sorted list without altering the previous one. For example:-

numbers = [5, 2, 7, 1, 9]
sorted_numbers = sorted(numbers)
print(sorted_numbers)  # Output: [1, 2, 5, 7, 9]

Using the ‘sort()’ method of the list object itself is another way to sort a list in place, which alters the original list.  For example:-

numbers = [5, 2, 7, 1, 9]
numbers.sort()
print(numbers)  # Output: [1, 2, 5, 7, 9]

Both ‘sorted()’ and ‘sort()’ sort the elements’ values by default in ascending order. However, by including more options, you can define a unique sorting order. For example, to sort a list of strings in descending order, you can use the `reverse=True` parameter:-

fruits = ['apple', 'banana', 'cherry', 'date']
sorted_fruits = sorted(fruits, reverse=True)
print(sorted_fruits)  # Output: ['date', 'cherry', 'banana', 'apple']

Programming’s fundamental action of sorting is applicable to more types of data structures than only lists. It enables you to organize components in a particular sequence to make them easier to use or to draw forth valuable insights from the data.

What is the use of sorted function in Python?

Python’s’sorted()’ method is used to arrange a group of elements in a particular hierarchy. Without changing the original collection, it accepts an iterable as input, such as a list, tuple, or string, and returns a new sorted list. By default, the sorted list will be organized in ascending order.

The `sorted()` function is useful in various scenarios:

Sorting Lists: A list of elements can be sorted using the ‘sorted()’ function. This is useful if you wish to arrange the components in a particular sequence for simpler processing or presentation. For example:-

numbers = [5, 2, 7, 1, 9]
sorted_numbers = sorted(numbers)
print(sorted_numbers)  # Output: [1, 2, 5, 7, 9]

Sorting Strings: ‘sorted()’ can also be used to sort the characters in a string. Based on the characters’ Unicode values, it returns a new string with the characters sorted in ascending order. For example:-

text = "python"
sorted_text = sorted(text)
print(sorted_text)  # Output: ['h', 'n', 'o', 'p', 't', 'y']

Custom Sorting: To change the sorting order, add more arguments to the ‘sorted()’ function. For instance, you can sort in decreasing order using the’reverse=True’ argument. Additionally, you may construct a function that computes a value for each element and utilizes that value for sorting by specifying a custom sorting key using the ‘key’ parameter. When you wish to sort based on particular criteria, this is useful. Here’s an example:-

names = ['Alice', 'bob', 'Charlie', 'dave']
sorted_names = sorted(names, key=lambda x: x.lower())
print(sorted_names)  # Output: ['Alice', 'bob', 'Charlie', 'dave']

In the above example, Using the ‘key’ option, the names are converted to lowercase and sorted without regard to the case.

Sorting Custom Objects: By specifying a key function that extracts a value to compare the objects, “sorted()” can be used to order a collection of unique items. This enables you to order objects according to a set of criteria or properties. Here’s a simplified example:-

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

people = [
    Person('John', 25),
    Person('Alice', 30),
    Person('Bob', 20)
]

sorted_people = sorted(people, key=lambda x: x.age)
for person in sorted_people:
    print(person.name, person.age)


The objects of the `Person` class are sorted based on their age attribute, resulting in the output:-

Bob 20
John 25
Alice 30

Ways to Sort a List in Python Without the Sort Function

 The topic of sorting a list in Python without using the “sort()” method will be introduced in this part, which also serves as the article’s introduction. We will provide background for the various sorting techniques on how to sort a List in Python Without the Sort Function we will examine and explain why such scenarios might occur.

Using the Sorted() Function:– The ‘Sorted()’ function in Python, which is a replacement for the ‘sort()’ function, will be covered in this part. We’ll outline its operation and provide examples to illustrate how to use it.

Implementing Bubble Sort:- Bubble Sort is a straightforward sorting algorithm that iteratively steps over the list, compares nearby components, and swaps them if they are out of order. We’ll go into great detail on the algorithm and offer a Python implementation.

Applying Selection Sort:- Selection Sort works by repeatedly selecting the first entry from the list’s unsorted section that is the smallest value. The algorithm will be described, and a Python implementation will be offered.

Utilizing Insertion Sort:- Insertion One item at a time, Sort creates the final sorted list. In each iteration of the list, each element is compared to the piece that has already been sorted, and then it is inserted in the proper place. The algorithm will be covered, and a Python implementation will be given.

Exploring Merge Sort:- Merge Divide and conquer is a strategy used in the sort algorithm, which separates the list into smaller sublists, sorts them, and then combines them to create a sorted list. The algorithm will be described, and a Python implementation will be offered. How to sort a List in Python Without the Sort Function is very eased by this function.

Trying Quick Sort:- Quick Sort is another divide-and-conquer algorithm that divides the other elements around a pivot element that is chosen. The algorithm will be described, and a Python implementation will be offered.

Employing Heap Sort:– Heap Sort utilizes the concept of a binary heap to sort the list. We will explain the heap data structure and the steps involved in the Heap Sort algorithm, along with a Python implementation.

Implementing Radix Sort:– RadixSort is a non-comparative integer sorting algorithm that sorts the list by grouping numbers by individual digits. We will discuss the algorithm and provide a Python implementation.

Applying Counting Sort:- Counting Sort is another non-comparative integer sorting algorithm that works by determining the number of occurrences of each element and using this information to determine their final positions. After that, an algorithm will be offered and implementation of Python will also be provided.

Utilizing Bucket Sort:- Bucket Sort divides the list into equally sized intervals, called buckets, and then sorts the elements within each bucket. Upon discussing the algorithm used, a Python application on it will be provided.

Exploring Tim Sort:- Tim Sort is a hybrid sorting algorithm derived from Merge Sort and Insertion Sort. It is the default sorting algorithm in Python’s `sort()` function which uses an algorithm and requires a Python implementation.

Employing Cocktail Shaker Sort:- Cocktail Shaker Sort, also known as Bidirectional Bubble Sort, is a variation of Bubble Sort that sorts the list in both directions. Using an algorithm succeeded by the Python application.

Conclusion

In this article, we explored various methods to sort a List in Python Without the Sort Function. We discussed each algorithm in detail and provided Python implementations for all of them. By understanding these alternative sorting techniques, you now have the knowledge and flexibility to tackle sorting scenarios where the `sort()` function is not available or suitable.