Hello everyone, Welcome to Programming In Python. Here you will know about few best Python One-Liners. Let’s get started.
Python is one of the most powerful and beginner-friendly programming languages, known for its simplicity and readability. But did you know that Python also allows you to perform complex tasks in just a single line of code? In this blog post, we will explore 20 powerful Python one-liners that can help you write more efficient and concise code. Whether you are a beginner or an experienced developer, these tricks will definitely save you time and effort.
1. Swap Two Variables
Swapping two variables usually requires a temporary variable, but in Python, you can do it in one line.
a, b = b, a
This swaps the values of a and b without requiring an extra variable.
Example
a, b = 5, 10 a, b = b, a print(a, b) # Output: 10 5
2. Reverse a List
Want to reverse a list without using a loop? Try this
reversed_list = my_list[::-1]
This slicing trick reverses the list instantly.
Example
my_list = [1, 2, 3, 4, 5] reversed_list = my_list[::-1] print(reversed_list) # Output: [5, 4, 3, 2, 1]
3. Merge Two Dictionaries
Combining two dictionaries can be done effortlessly.
merged_dict = {**dict1, **dict2}
This merges dict1 and dict2 into a single dictionary.
Example
dict1 = {'a': 1, 'b': 2}
dict2 = {'c': 3, 'd': 4}
merged_dict = {**dict1, **dict2}
print(merged_dict) # Output: {'a': 1, 'b': 2, 'c': 3, 'd': 4}
4. Check if a String is a Palindrome
A simple way to check if a string reads the same forward and backward.
s == s[::-1]
Example
is_palindrome = lambda s: s == s[::-1]
print(is_palindrome("madam")) # Output: True
Returns True if the string is a palindrome.
5. Find Factorial of a Number
Instead of using loops, get factorial using the math module.
math.factorial(5)
This returns 120, which is 5!
Example
import math fact = math.factorial(5) print(fact) # Output: 120
6. Get Unique Elements from a List
Remove duplicates from a list quickly.
unique_items = list(set(my_list))
Using set() ensures that only unique elements remain.
Example
my_list = [1, 2, 2, 3, 4, 4, 5] unique_items = list(set(my_list)) print(unique_items) # Output: [1, 2, 3, 4, 5]
7. Find the Most Frequent Element in a List
Determine the most common element in a list.
max(set(my_list), key=my_list.count)
This finds the item that appears the most times in my_list.
Example
my_list = [1, 3, 2, 3, 4, 3, 5] most_frequent = max(set(my_list), key=my_list.count) print(most_frequent) # Output: 3
8. Read a File in One Line
Read all lines from a file using a list comprehension.
[line.strip() for line in open("file.txt")]
Example
lines = [line.strip() for line in open("file.txt")]
print(lines)
This creates a list of stripped lines from the file.
9. Check if a Number is Even
Use a lambda function to check if a number is even.
lambda x: x % 2 == 0
Example
is_even = lambda x: x % 2 == 0 print(is_even(4)) # Output: True
Returns True if x is even, False otherwise.
10. Flatten a Nested List
Convert a nested list into a single list.
[item for sublist in nested_list for item in sublist]
Example
nested_list = [[1, 2, 3], [4, 5], [6]] flat_list = [item for sublist in nested_list for item in sublist] print(flat_list) # Output: [1, 2, 3, 4, 5, 6]
This eliminates the need for nested loops.
11. Transpose a Matrix
Switch rows and columns in a matrix.
list(zip(*matrix))
Example
matrix = [[1, 2, 3], [4, 5, 6]] transposed = list(zip(*matrix)) print(transposed) # Output: [(1, 4), (2, 5), (3, 6)]
A quick way to transpose a 2D list.
12. Get the Index of the Maximum Element in a List
Find the index of the largest element.
my_list.index(max(my_list))
Example
my_list = [1, 3, 7, 2] max_index = my_list.index(max(my_list)) print(max_index) # Output: 2
Returns the position of the highest value in the list.
13. Convert a List of Tuples to a Dictionary
dict(tuple_list)
Example
tuple_list = [("a", 1), ("b", 2), ("c", 3)]
my_dict = dict(tuple_list)
print(my_dict) # Output: {'a': 1, 'b': 2, 'c': 3}
Converts a list of key-value pairs into a dictionary.
14. Find the Intersection of Two Lists
list(set(list1) & set(list2))
Example
list1 = [1, 2, 3, 4] list2 = [3, 4, 5, 6] intersection = list(set(list1) & set(list2)) print(intersection) # Output: [3, 4]
Finds common elements between two lists.
15. Remove Falsy Values from a List
list(filter(bool, values))
Example
values = [0, 1, False, 2, '', 3, None] filtered_values = list(filter(bool, values)) print(filtered_values) # Output: [1, 2, 3]
Removes False, 0, None, and empty strings from a list.
16. Generate a List of Squares
[x**2 for x in range(1, 6)]
Example
squares = [x**2 for x in range(1, 6)] print(squares) # Output: [1, 4, 9, 16, 25]
Creates a list of squares of numbers from 1 to 5.
17. Find the Length of the Longest Word in a Sentence
max(len(word) for word in sentence.split())
Example
sentence = "Python is an amazing programming language" longest_word_length = max(len(word) for word in sentence.split()) print(longest_word_length) # Output: 11
Finds the longest word length.
18. Shuffle a List Randomly
random.shuffle(my_list)
Example
import random my_list = [1, 2, 3, 4, 5] random.shuffle(my_list) print(my_list)
Shuffles the list randomly.
19. Generate a Random Password
''.join(random.choices(string.ascii_letters + string.digits, k=8))
Example
import string, random password = ''.join(random.choices(string.ascii_letters + string.digits, k=8)) print(password)
Creates a random 8-character password.
20. Convert a String to Title Case
text.title()
Example
text = "hello world" print(text.title()) # Output: Hello World
Converts a string to title case.
Conclusion
Mastering Python one-liners can help you write more efficient and elegant code. These 20 examples showcase Python’s powerful and concise syntax. Try incorporating them into your projects and see how they improve your coding efficiency!
Wanna know about best Python Libraries for AI, check these articles on Numpy, Pandas, TensorFlow, MatplotLib.
