25 Essential Python Code Snippets to Boost Your Everyday Programming

Python is a versatile high‑level programming language that can be used to develop desktop GUI applications, websites, and web services.

Its clear syntax lets you concentrate on core logic for common programming tasks.

Compared with other languages, Python offers several advantages:

Cross‑platform compatibility

Abundant open‑source frameworks and tools

Readable and maintainable code

Robust standard library

Support for test‑driven development

The following sections introduce 25 simple and useful code snippets that help you accomplish everyday tasks.

1. Swap values between two variables

Python makes swapping values without a temporary variable straightforward using tuple unpacking.

a = 5
b = 10
a, b = b, a
print(a)  # 10
print(b)  # 5

2. Check if a number is even

This function returns True for even numbers and False otherwise.

def is_even(num):
    return num % 2 == 0

print(is_even(10))  # True

3. Split a multiline string into a list

The function splits a multiline string into a list of lines.

def split_lines(s):
    return s.split('
')

lines = split_lines('50
python
snippets')
print(lines)  # ['50', 'python', 'snippets']

4. Get the memory size of an object

Use the sys.getsizeof() function to obtain the size of an object in bytes.

import sys
print(sys.getsizeof(5))        # 28
print(sys.getsizeof('Python')) # 55

5. Reverse a string

Python’s slicing syntax can reverse a string in a single expression.

language = "python"
reversed_language = language[::-1]
print(reversed_language)  # nohtyp

6. Print a string n times without a loop

Multiplying a string by an integer repeats it n times.

def repeat(string, n):
    return string * n

print(repeat('python', 3))  # pythonpythonpython

7. Check if a string is a palindrome

The function returns True when the string reads the same forwards and backwards.

def palindrome(string):
    return string == string[::-1]

print(palindrome('python'))  # False

8. Join a list of strings into a single comma‑separated string

Use str.join() to concatenate list elements.

strings = ['50', 'python', 'snippets']
print(','.join(strings))  # 50,python,snippets

9. Retrieve the first element of a list

This function returns the element at index 0.

def head(lst):
    return lst[0]

print(head([1, 2, 3, 4, 5]))  # 1

10. Merge two lists and remove duplicates

Combine two lists and return a list of unique elements.

def union(a, b):
    return list(set(a + b))

print(union([1, 2, 3, 4, 5], [6, 2, 8, 1, 4]))  # [1, 2, 3, 4, 5, 6, 8]

11. Get all unique elements from a list

Convert the list to a set and back to a list.

def unique_elements(numbers):
    return list(set(numbers))

print(unique_elements([1, 2, 3, 2, 4]))  # [1, 2, 3, 4]

12. Compute the average of numbers

Accept a variable number of arguments and return their arithmetic mean.

def average(*args):
    return sum(args) / len(args)

print(average(5, 8, 2))  # 5.0

13. Verify that all elements in a list are unique

Compare the length of the list with the length of its set representation.

def unique(lst):
    if len(lst) == len(set(lst)):
        print("All elements are unique")
    else:
        print("List has duplicates")

unique([1, 2, 3, 4, 5])  # All elements are unique

14. Count the frequency of each element in a list

Use collections.Counter to obtain a dictionary of element frequencies.

from collections import Counter
lst = [1, 2, 3, 2, 4, 3, 2, 3]
count = Counter(lst)
print(count)  # Counter({2: 3, 3: 3, 1: 1, 4: 1})

15. Find the most frequent element in a list

Return the element with the highest occurrence count.

def most_frequent(lst):
    return max(set(lst), key=lst.count)

numbers = [1, 2, 3, 2, 4, 3, 1, 3]
print(most_frequent(numbers))  # 3

16. Convert degrees to radians

Apply the formula radians = degrees * π / 180.

import math
def degrees_to_radians(deg):
    return (deg * math.pi) / 180.0

print(degrees_to_radians(90))  # 1.5707963267948966

17. Measure execution time of a code block

Use time.time() to calculate elapsed microseconds.

import time
start_time = time.time()
a, b = 5, 10
c = a + b
end_time = time.time()
time_taken = (end_time - start_time) * (10**6)
print("Time taken in micro_seconds:", time_taken)
# Example output: Time taken in micro_seconds: 39.577484130859375

18. Compute the greatest common divisor of a list of numbers

Apply functools.reduce with math.gcd.

from functools import reduce
import math
def gcd(numbers):
    return reduce(math.gcd, numbers)

print(gcd([24, 108, 90]))  # 6

19. Extract unique characters from a string

Convert the string to a set and join the result.

string = "abcbcabdb"
unique = set(string)
new_string = ''.join(unique)
print(new_string)  # abcd (order may vary)

20. Use a lambda function

Lambda creates an anonymous function for a single expression.

x = lambda a, b, c: a + b + c
print(x(5, 10, 20))  # 35

21. Apply a function with map

Map a function over an iterable and collect the results.

def multiply(n):
    return n * n

lst = (1, 2, 3)
result = map(multiply, lst)
print(list(result))  # [1, 4, 9]

22. Filter a sequence with filter

Keep only elements that satisfy a predicate.

arr = [1, 2, 3, 4, 5]
arr = list(filter(lambda x: x % 2 == 0, arr))
print(arr)  # [2, 4]

23. List comprehension example

Create a new list by applying an expression to each element of an existing list.

numbers = [1, 2, 3]
squares = [number**2 for number in numbers]
print(squares)  # [1, 4, 9]

24. Slice (rotate) a list

Rotate a list by a given offset using slicing.

def rotate(arr, d):
    return arr[d:] + arr[:d]

arr = [1, 2, 3, 4, 5]
arr = rotate(arr, 2)
print(arr)  # [3, 4, 5, 1, 2]

25. Chain function calls

Demonstrate calling multiple functions in a single expression.

def add(a, b):
    return a + b

def subtract(a, b):
    return a - b

a, b = 5, 10
print(subtract(add(a, b), a))  # 10