What is Python sorted() Function?

Python sorted() is a built-in function that you’ll find really handy in your codes. It’s designed to help you sort iterable objects like lists, tuples, and strings. When you use sorted(), it gives you a new sorted list with the elements from your original iterable, sorted either in ascending or descending order.

Depending on your needs, you can customize the sorting process using optional keyword arguments like key to define specific sorting criteria within your elements and reverse to control whether you want the sorting order to be ascending (which is the default) or descending. This function is a fantastic tool to keep in your coding arsenal for sorting and organizing data easily.

To get more clear picture of Python sorted() function let’s imagine you’re in a bustling marketplace, and you want to arrange your items in order. The Python sorted() function is your trusted helper—it sorts data, whether it’s a list of numbers, a collection of names, or any other iterable, making your life easier.

Now that you have a grasp of the fundamental aspects of the Python sorted(), let’s examine its syntax and parameters, which hold significant importance for efficiently running the provided examples.

Python sorted() Syntax and Parameters

The syntax of the sorted() function is refreshingly straightforward. It involves invoking the function and providing an iterable as its input, as shown in the following format:

sorted(iterable, key=None, reverse=False)

When you’re working with the Python sorted() function, it’s important to note that it requires three parameters. The first one is mandatory, and it’s called the iterable or sequence, which is the collection of items you want to sort. The other two parameters, key and reverse, are optional. Now, let’s take a closer look at these parameters to get a better grasp of how they function.

I. Iterable (mandatory)

The iterable parameter represents a sequence such as string, tuple, or a collection like a set, dictionary, or frozen set, or any other kind of iterator that you provide.

II. Key (optional)

The key parameter, when set to True, reverses the sorted list, which means it sorts the list in descending order. If you don’t provide this parameter, it defaults to False.

III. Reverse (optional)

The reverse parameter is a function that acts as a reference point for sorting comparisons. If you don’t specify this parameter, it defaults to None.

Having a solid understanding of Python sorted() syntax and parameters, let’s explore its return value to see how it works in practical scenarios.

Python sorted() Return Value

The return value of the Python sorted() is a fresh list that contains all the elements extracted from the original iterable (sequence or collection). By default, these elements are sorted in ascending order, but you can alter the sorting order. Importantly, the original iterable remains unaltered, ensuring that your original data structure remains intact while providing you with a sorted version of its contents. Consider the following illustration:

In this example, we start with an unsorted list of numbers called unsorted_numbers, which contains [5, 2, 9, 1, 5]. Our aim is to arrange this list in ascending sequence.. To do this, we use the sorted() function.

We pass our unsorted_numbers list as an argument to the sorted() function, which creates a new list called sorted_numbers containing the same elements but sorted in ascending order. Finally, we print sorted_numbers, by using print() function.

As showcase in the example above, you can efficiently arrange the items within a list by employing the Python sorted() function.

As previously stated, the sorted() function is primarily utilized for sorting tasks. Now, let’s move on and examine practical scenarios where the Python sorted() function comes into play in different situations.

I. Python sorted() with String

In Python, When you apply sorted() to a string, it organizes the individual characters within the string according to their alphabetical order, akin to arranging words in a dictionary. This functionality is particularly useful if you’re a linguist investigating the occurrence of letters in a sentence.

In this context, the sorted() function serves as your linguistic instrument, enabling you to arrange the letters in alphabetical order for meticulous analysis. Here’s an example of how you can use sorted() with a string:

Here, we have a sentence stored in the variable sentence, which reads, Python is the most popular programming language. To analyze and manipulate the sentence, we decided to use Python’s sorted() function. It’s a handy tool that can sort elements in a sequence, like characters in a string, and return a new sequence with those elements arranged in a specific order.

So, we applied the sorted() function to our sentence. This meant taking each character in the sentence and sorting them lexicographically, much like arranging words in a dictionary. The result, which we stored in the variable sorted_sentence, is a list containing all the characters from the original sentence but sorted in alphabetical order. To see the sorted result, we used the print() function to display sorted_sentence. When we run the code, it will print the characters from our sentence sorted alphabetically on the screen.

This is helpful if you want to analyze the characters in the sentence in a different order, perhaps for further linguistic or computational processing.

II. Python sorted() in Descending Order

You can also sort elements in descending order in Python by using the sorted() function and specifying the reverse parameter as True. By default, when you use sorted(), it arranges elements in ascending order. However, when you set reverse=True, the function will arrange the elements in descending order. This can be particularly useful when you need to reverse the elements in which data is sorted. To illustrate, here’s an example:

For this example, we have a tuple called vintage_years, which contains a series of years denoting different vintage points: 1960, 1975, 1985, 1995, and 2005. Our goal here is to sort these years in descending order, so we know the most recent vintage years first. To do this, we’ve used Python’s sorted() function.

First, we decided to sort vintage_years in reverse order, and we accomplished this by setting the reverse parameter to True within the sorted() function.  Once we’ve sorted the years, we want to display the result to the user. So, we used the print() function to output the years, which are stored in the variable sorted_years_desc. When we run this code, it will print Reversed years are: followed by the years sorted in backward order, allowing us to see the vintage years in reverse chronological order.

This technique leverages the flexibility and simplicity of Python sorted(), allowing you to efficiently manipulate and display your data in the desired way.

III. Python sorted() with len()

Python sorted() can be employed alongside the len() function to arrange a group of elements according to their size, whether it’s the number of items they contain or the characters within each element. This can be a valuable technique, especially when dealing with lists of strings or other sequences, where you may want to organize them in a way of their lengths. To showcase this approach, consider the following example:

In this example, we have a set called books that contains the titles of various books. Our goal is to sort these book titles based on their lengths, arranging them in an order. To achieve this, we’ve used Python’s sorted() function and provided the key=len parameter, indicating that we want to classify the titles based on the length . After sorting, we’ve created a new set called sorted_books_by_length to store the sorted titles. This set now contains the book titles organize from shortest to longest.

To display the result, we use the print() function, which shows the contents of the sorted_books_by_length set. This allows us to see the book titles organized by their respective lengths.

As a result, the above example provides you with an organized and ordered set of book titles, helping you better understand and manipulate the information based on the lengths.

IV. Python Sorted() with Lambda

In Python, you can use the sorted() function with a lambda function  to categorize a collection of elements based on a custom criterion defined by the lambda function. This allows you to classify elements in a way that may not be achievable using the default sorting behavior. For instance:

Here, we have a collection of data points stored in a variable called data_points. Each data point consists of a pair of values, where the first value represents one aspect of the data, and the second value represents another aspect. In our specific case, the data points are as follows: (3, 4), (1, 2), (5, 1), and (2, 3).

Our goal here is to arrange these data points based on the second value of each pair, meaning we want to rearrange them in an order of the second aspect of the data. To achieve this, we use the sorted() function. Then we’re using a lambda function as the key parameter. This lambda function takes an individual data point x and returns x[1], which means it’s telling the sorted() function to organize the data points based on their second values.

After applying the sorted() function to our data_points, we store the result in a variable called sorted_data. So, sorted_data now contains the sorted data points. Next, we have the line tuple_sort = (sorted_data). This line is creating a new variable called tuple_sort and assigning it the value of sorted_data.  Finally, we print the tuple_sort variable, which contains the data points sorted in ascending order of their second values.

It illustrates the use of the sorted() function with a custom sorting key, achieved through a lambda function, to manipulate and organize data.

Python sorted Advanced Examples

In the upcoming section, we’ll explore various advanced instances of the Python sorted() function, showcasing its flexibility and extensive array of uses.

I. Python sorted() with Conditional Statements

The sorted() function, when used with conditional statements through the key parameter, allows you to organize elements from an iterable, based on custom defined by a provided function. This function, often implemented as a lambda function or a custom function, calculates a value for each element, and sorted() arranges the elements in a way based on these calculated values.

This feature enables you to perform conditional sorting, where elements are ordered according to specific conditions or criteria you specify in the key function, providing flexibility for sorting data based on various factors like length, absolute value, or any other custom logic. Consider below illustration:

For this example, we begin by defining a function named is_prime(num) to determine whether a given number is prime or not. To accomplish this, we utilize a series of examinations. If the number is less than or equal to 1, we immediately return False since primes must be greater than 1. If the number is precisely 2, we return True, as it is a prime number. If the number is even (divisible by 2), we again return False, as no even number (except 2) can be prime. Finally, we employ a loop to check if the number is divisible by any odd integer from 3 up to the square root of the number plus 1. If it is divisible by any of these odd numbers, we return False, indicating it’s not prime. Otherwise, we return True, signifying it is a prime number.

Next, we initialize a set called numbers containing a collection of integers. This set includes both prime and non-prime numbers in a random order. Now, we want to sort this set, but with a special condition in mind: we want prime numbers to come first in ascending order, followed by non-prime numbers in ascending order.

To achieve this, we use the sorted() function, specifying a custom key function. This key function takes each number x from the set and constructs a tuple. The first element of the tuple is a Boolean value, not is_prime(x), which evaluates to True for non-prime numbers and False for prime numbers. The second element of the tuple is the number itself, x. By sorting based on this tuple, we ensure that prime numbers come first, sorted in ascending order, and then non-prime numbers follow, also sorted in ascending order.

Finally, we create a new set called sorted_set_prime_numbers from the sorted list, which removes any duplicate elements. When we print sorted_set_prime_numbers, it will display the sorted unique prime numbers followed by the sorted unique non-prime numbers, achieving the desired result.

As you can observe in the above example, this approach allows you to seamlessly prioritize and sort prime numbers at the beginning of the sorted list, followed by the non-prime numbers, making complex sorting tasks straightforward and highly customizable in Python.

II. Sorting Dictionaries by Key with sorted()

Sorting dictionaries by key with the sorted() function in Python arranges the dictionary’s key-value pairs based on the keys. This process involves extracting the key-value pairs into a list of tuples using the items() method, sorting those tuples using sorted(), and then converting the sorted list of tuples back into a dictionary.

The result is a dictionary where the keys are organized in ascending order, making it easier to access and manipulate the dictionary's data in a predictable manner. This sorting operation is helpful when you need to work with the dictionary in a specific order based on the keys, such as when you want to iterate through the dictionary or present its contents in an organized fashion. For instance:

In this example, Firstly, we define a class called SortedDict. This class has a constructor method __init__ which takes a dictionary, my_dict, as an argument. Inside the constructor, we store this dictionary in an instance variable, self.my_dict, so that it can be accessed throughout the class methods.

Within the SortedDict class, we have a method named sort_by_keys. This method sorts the dictionary stored in self.my_dict by its keys using the sorted() function and returns the sorted dictionary. We create an instance of the SortedDict class, sorted_dict_instance, passing our sample dictionary my_dict as its argument.

We also have a standalone function outside the class, sort_dict_by_keys, which does the same task of sorting a dictionary by its keys. This function accepts a dictionary as an argument and returns the sorted dictionary. Now, we have our sample dictionary my_dict, which contains a mix of even and odd keys paired with corresponding values.

We proceed to use the SortedDict class by creating an instance, sorted_dict_instance, and then calling its sort_by_keys method. This sorts our my_dict by its keys and stores the result in sorted_result_instance. Additionally, we utilize the standalone function sort_dict_by_keys, passing my_dict as its argument, and store the sorted result in sorted_result_function. Finally, we print out both sorted dictionaries, indicating whether we are using the class method or the standalone function.

By using this approach you can easily sort a dictionary by its keys using both a class and a standalone function.

III. Handling Exceptions and Errors with sorted()

Handling exceptions and errors with sorted() in Python involves managing situations where the sorting process might encounter issues, such as incompatible data types or missing keys in dictionaries. By addressing these exceptions, you can ensure that your code gracefully handles potential errors during sorting.

This may include catching TypeError instances when trying to sort uncomparable elements, specifying custom sorting criteria using the key parameter, reversing the sorting order with the reverse parameter, or handling missing keys in dictionaries to prevent KeyError exceptions. Efficiently handling these exceptions helps make your code more resilient and robust, ensuring that it functions as intended even when unexpected data or conditions arise during the sorting process. For example:

Here, we have a list called data that contains a mix of different data types, including integers, strings, and a floating-point number. We start by attempting to sort this data list using the sorted() function within a try block. However, things can get tricky because sorting mixed data types can lead to a TypeError due to the incompatibility of certain elements. If such an exception occurs during sorting, we catch it using the except block, where we print an error message indicating the nature of the TypeError.

To address this issue, we take a proactive approach. Inside the except block, we create a new list named filtered_data using a list comprehension. This list comprehension iterates through the elements in the original data list and includes only those that are either integers or floating-point numbers, filtering out non-comparable elements like strings.

Once we’ve filtered the data, we proceed to sort this sanitized filtered_data list using sorted() and assign the sorted result back to sorted_data. This ensures that we are working with comparable elements. Finally, outside the try and except blocks, we print the sorted_data, which now contains the sorted, compatible elements from the original data list.

This code showcases a practical approach to handling exceptions during sorting by filtering out non-comparable elements and successfully obtaining a sorted result.

Advantages of python sorted()

Here are some advantages of the Python sorted() function that can be quite valuable to understand:

I. Ease of Use

You can easily sort various iterable data structures like lists, tuples, and dictionaries with sorted(), making it accessible for different use cases.

II. Readable Code

It makes your code more readable and maintainable compared to implementing sorting algorithms manually.

III. Stability

Python’s sorted() function is stable, meaning it preserves the relative order of equal elements. This is useful in scenarios where you want to sort by multiple criteria.

Practical Usage of sorted()

Python sorted() function has a wide range of practical applications. Here are some practical use cases where sorted() can be very helpful:

I. Custom Sorting

You can employ the key parameter to perform custom sorting based on specific criteria. For instance, sorting a list of dictionaries by a particular key.

II. Removing Duplicates

By sorting a list and converting it into a set, you can remove duplicate elements, as sets only contain unique values.

III. Displaying Data

Python Sorted() is handy for presenting data in a more organized and readable manner, such as sorting results in a table.

Congratulation! You’ve now learned Python sorted() function and explored its myriad of practical applications. This built-in function serves as a flexible and convinient tool in your coding arsenal, simplifying the task of sorting iterable objects. It not only eases the sorting process but also provides customization options, allowing you to define specific sorting criteria and even reverse the order easily.

In this Python Helper guide, you’ve gained knowledge and delved into the features and potential of the Python sorted() function. You’ve discovered its applications with strings, lists, and tuples, and beyond that, you’ve explored how it can be used with custom functions, sets, and dictionaries. Additionally, you’ve acquired insights into handling exceptions and errors that may arise when working with the sorted() function in Python.

So, as you continue your coding journey, remember that Python sorted() function is here to streamline your sorting tasks, enhance your code’s readability, and offer flexibility for a wide range of use cases. With this tool at your disposal, you’re well-equipped to tackle sorting challenges and organize data efficiently. Keep coding and exploring the endless possibilities that Python has to offer!