25 Insanely Useful Python Code Snippets For Everyday Problems

 

📝 1. Swap Two Variables Without a Temp Variable

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

Output:

10 5

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📏 2. Check if a String is a Palindrome

def is_palindrome(s):
    return s == s[::-1]
print(is_palindrome("madam"))

Output:

True

---

🔢 3. Find the Factorial of a Number

from math import factorial
print(factorial(5))

Output:

120

---

🎲 4. Generate a Random Password

import secrets, string

def random_password(length=10):
    chars = string.ascii_letters + string.digits + string.punctuation
    return ''.join(secrets.choice(chars) for _ in range(length))
print(random_password())

Output:

e.g., "A9$uT1#xQ%"

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🔄 5. Flatten a Nested List

def flatten(lst):
    return [i for sublist in lst for i in sublist]
print(flatten([[1, 2], [3, 4]]))

Output:

[1, 2, 3, 4]

---

🎭 6. Check if Two Strings are Anagrams

from collections import Counter

def is_anagram(s1, s2): 
    return Counter(s1) == Counter(s2)

print(is_anagram("listen", "silent"))

Output:

True

---

🛠️ 7. Merge Two Dictionaries

d1, d2 = {'a': 1}, {'b': 2}
merged = {**d1, **d2}
print(merged)

Output:

{'a': 1, 'b': 2}

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📅 8. Get the Current Date and Time

from datetime import datetime
print(datetime.now())

Output:

2025-02-18 14:30:45.123456

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🏃 9. Find Execution Time of a Function

import time

start = time.time()
time.sleep(1)
print(time.time() - start)

Output:

1.001234 (approx.)

---

📂 10. Get the Size of a File

import os
print(os.path.getsize("example.txt"))

Output:

e.g., 1024 (size in bytes)

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🔎 11. Find the Most Frequent Element in a List

from collections import Counter

def most_frequent(lst):
    return Counter(lst).most_common(1)[0][0]

print(most_frequent([1, 2, 3, 1, 2, 1]))

Output:

1

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🔢 12. Generate Fibonacci Sequence

def fibonacci(n):
    a, b = 0, 1
    for _ in range(n):
        yield a
        a, b = b, a + b 

print(list(fibonacci(10)))

Output:

[0, 1, 1, 2, 3, 5, 8, 13, 21, 34]

---

🔄 13. Reverse a List in One Line

lst = [1, 2, 3, 4]
print(lst[::-1])

Output:

[4, 3, 2, 1]

---

🔍 14. Find Unique Elements in a List

print(list(set([1, 2, 2, 3, 4, 4])))

Output:

[1, 2, 3, 4]

---

🎯 15. Check if a Number is Prime

def is_prime(n):
    return n > 1 and all(n % i for i in range(2, int(n**0.5) + 1))

print(is_prime(7))

Output:

True

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📜 16. Read a File in One Line

print(open("example.txt").read())

Output:

Contents of the file

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📝 17. Count Words in a String

def word_count(s):
    return len(s.split())

print(word_count("Hello world!"))

Output:

2

---

🔄 18. Convert a List to a Comma-Separated String

lst = ["apple", "banana", "cherry"]
print(", ".join(lst))

Output:

apple, banana, cherry

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🔀 19. Shuffle a List Randomly

import random
lst = [1, 2, 3, 4]
random.shuffle(lst)
print(lst)

Output:

e.g., [3, 1, 4, 2]

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🔢 20. Convert a List of Strings to Integers

lst = ["1", "2", "3"]
print(list(map(int, lst)))

Output:

[1, 2, 3]

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🔗 21. Get the Extension of a File

print("example.txt".split(".")[-1])

Output:

txt

---

📧 22. Validate an Email Address

import re

def is_valid_email(email):
    return bool(re.match(r"[^@]+@[^@]+\.[^@]+", email))

print(is_valid_email("test@example.com"))

Output:

True

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📏 23. Find the Length of the Longest Word in a Sentence

def longest_word_length(s):
    return max(map(len, s.split()))

print(longest_word_length("Python is awesome"))

Output:

7

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🔠 24. Capitalize the First Letter of Each Word

print("hello world".title())

Output:

Hello World

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🖥️ 25. Get the CPU Usage Percentage

import psutil
print(psutil.cpu_percent(interval=1))

Output:

e.g., 23.4