Here are four ways to sort a list alphabetically in Python.
- Using the sorted() method
- Using the sort() method
- Sort a list alphabetically using a key
- Using a custom function
Method 1: Using the sorted() method
To sort a list alphabetically in Python, the easiest way is to use the “sorted()” method. The sorted() function sorts the given iterable object in a specific order, either ascending or descending.
The sorted(iterable, key=None) method takes an optional key that specifies how to sort.
To disregard capitalization when sorting a list, set the key to str.
Follow the below steps to sort a list alphabetically.
Step 1: Create a list of strings
Use the square brackets [ ] and add the strings separated by a comma to create a list of strings.
data = ['Elle', 'Miles', 'Kratos', 'Joel', 'Peter', 'Nathan']Step 2: Pass the list of strings to the sorted() function
data = ['Elle', 'Miles', 'Kratos', 'Joel', 'Peter', 'Nathan']
print(sorted(data))Output
['Elle', 'Joel', 'Kratos', 'Miles', 'Nathan', 'Peter']And it returns a list of strings in ascending order.
One thing to note here is that we have not mixed a list with upper and lowercase strings.
data = ['Elle', 'miles', 'kratos', 'Joel', 'peter', 'Nathan']
print(sorted(data))Output
['Elle', 'Joel', 'Nathan', 'kratos', 'miles', 'peter']You can see that now the sorting is messed up. So let’s resolve this issue.
Step 3: Add a key parameter
As you can see, words that start with an uppercase letter get preference over those beginning with a lowercase letter.
To sort them independently, add the key parameter.
data = ['Elle', 'miles', 'kratos', 'Joel', 'peter', 'Nathan']
print(sorted(data, key=str.lower))Output
['Elle', 'Joel', 'kratos', 'miles', 'Nathan', 'peter']Step 4: Pass the reverse = True to the sorted() function
To reverse the order of the list, add the reverse argument and set it to True.
data = ['Elle', 'miles', 'kratos', 'Joel', 'peter', 'Nathan']
print(sorted(data, reverse=True))Output
['peter', 'miles', 'kratos', 'Nathan', 'Joel', 'Elle']The list.sort() function will sort it alphabetically. You can add reverse=False/True in the brackets to reverse the order of items: list.sort(reverse=False).
Method 2: Using the list sort() method
The list.sort() is a built-in Python function that sorts the elements of a list in low to high order.
If the list is of numbers, then by default, they will be sorted in increasing order.
Check out the below step-by-step guide to sort lists alphabetically using the list.sort() method.
Step 1: Create a list of strings with mixed cases
As we saw earlier, use the square brackets [] to create a list of strings with mixed cases.
data = ['Elle', 'miles', 'Kratos', 'joel', 'Peter', 'nathan']You can see that the list of strings consists of upper and lower cases.
Step 2: Use the .sort() method
You can call the .sort() method on the list and pass in the optional parameter “key=str.lower” that will tell the .sort() method to sort the list alphabetically, ignoring the case of the words.
data = ['Elle', 'miles', 'Kratos', 'joel', 'Peter', 'nathan']
data.sort(key=str.lower)
print(data)Output
['Elle', 'joel', 'Kratos', 'miles', 'nathan', 'Peter']You can see that it is sorted alphabetically regardless of the cases of the string.
Step 3: Sort the list in descending order
To sort the list in descending order, pass the optional parameter “reverse=True” to the .sort() method.
data = ['Elle', 'miles', 'Kratos', 'joel', 'Peter', 'nathan']
data.sort(key=str.lower, reverse=True)
print(data)Output
['Peter', 'nathan', 'miles', 'Kratos', 'joel', 'Elle']You can see the list.sort() function makes it easy to sort a list alphabetically in ascending or descending order in Python.
Method 3: Sort a List Alphabetically in Python with key
main_list = [('Krunal', 'Rajkot', 'Data Analyst'),
('Ankit', 'Ahmedabad', 'Software Developer'),
('Rushabh', 'Singapore', 'Data Scientist')]
sort_mylist = sorted(main_list, key=lambda x: x[1])
print(sort_mylist)Output
[('Ankit', 'Ahmedabad', 'Software Developer'),
('Krunal', 'Rajkot', 'Data Analyst'),
('Rushabh', 'Singapore', 'Data Scientist')]
Method 4: Using a custom function
In this method, we will sort a list alphabetically in Python without the “sort()” function.
def sort(lst):
if not lst:
return []
return (sort([x for x in lst[1:] if x < lst[0]])
+ [lst[0]] +
sort([x for x in lst[1:] if x >= lst[0]]))
s = ["Oppenheimer", "Louis", "Leslie", "Kitty", "Albert"]
print(sort(s))Output
['Albert', 'Kitty', 'Leslie', 'Louis', 'Oppenheimer']That’s it!
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Krunal Lathiya is a seasoned Computer Science expert with over eight years in the tech industry. He boasts deep knowledge in Data Science and Machine Learning. Versed in Python, JavaScript, PHP, R, and Golang. Skilled in frameworks like Angular and React and platforms such as Node.js. His expertise spans both front-end and back-end development. His proficiency in the Python language stands as a testament to his versatility and commitment to the craft.
