30 Handy Python Code Snippets for Everyday Tasks

This article introduces a collection of 30 short Python code snippets that can be learned in 30 seconds or less, each solving a specific everyday programming problem.

1. Check for duplicate elements

def all_unique(lst):
    return len(lst) == len(set(lst))

x = [1,1,2,2,3,2,3,4,5,6]
y = [1,2,3,4,5]
print(all_unique(x))  # False
print(all_unique(y))  # True

2. Anagram detection

from collections import Counter

def anagram(first, second):
    return Counter(first) == Counter(second)

print(anagram("abcd3", "3acdb"))  # True

3. Memory usage check

import sys
variable = 30
print(sys.getsizeof(variable))  # 24

4. Byte size calculation

def byte_size(string):
    return len(string.encode('utf-8'))

print(byte_size('😀'))   # 4
print(byte_size('Hello World'))  # 11

5. Repeat string N times without a loop

n = 2
s = "Programming"
print(s * n)  # ProgrammingProgramming

6. Capitalize each word

s = "programming is awesome"
print(s.title())  # Programming Is Awesome

7. Chunk a list

from math import ceil

def chunk(lst, size):
    return list(map(lambda x: lst[x*size:x*size+size], list(range(0, ceil(len(lst)/size)))))

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

8. Compact a list (remove falsy values)

def compact(lst):
    return list(filter(bool, lst))

print(compact([0,1,False,2,3,'a','s',34]))  # [1,2,3,'a','s',34]

9. Convert a 2‑D array to its transpose

array = [[a, b], [c, d], [e, f]]
transposed = zip(*array)
print(list(transposed))  # [(a, c, e), (b, d, f)]

10. Chain comparisons

a = 3
print(2 < a < 8)   # True
print(1 == a < 2)  # False

11. Join list items with commas

hobbies = ["basketball", "football", "swimming"]
print("My hobbies are: " + ", ".join(hobbies))
# My hobbies are: basketball, football, swimming

12. Count vowels in a string

import re

def count_vowels(s):
    return len(re.findall(r"[aeiou]", s, re.IGNORECASE))

print(count_vowels("foobar"))  # 3
print(count_vowels("gym"))     # 0

13. Decapitalize first character

def decapitalize(string):
    return string[:1].lower() + string[1:]

print(decapitalize("FooBar"))  # fooBar

14. Flatten a nested list recursively

def spread(arg):
    ret = []
    for i in arg:
        if isinstance(i, list):
            ret.extend(i)
        else:
            ret.append(i)
    return ret

def deep_flatten(lst):
    result = []
    result.extend(spread([deep_flatten(x) if isinstance(x, list) else x for x in lst]))
    return result

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

15. Difference between two iterables

def difference(a, b):
    return list(set(a).difference(set(b)))

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

16. Difference by applying a function

def difference_by(a, b, fn):
    b_set = set(map(fn, b))
    return [item for item in a if fn(item) not in b_set]

from math import floor
print(difference_by([2.1, 1.2], [2.3, 3.4], floor))  # [1.2]

17. Chain function calls

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

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

a, b = 4, 5
print((subtract if a > b else add)(a, b))  # 9

18. Check for duplicates using set

def has_duplicates(lst):
    return len(lst) != len(set(lst))

print(has_duplicates([1,2,3,4,5,5]))  # True
print(has_duplicates([1,2,3,4,5]))    # False

19. Merge two dictionaries

def merge_two_dicts(a, b):
    c = a.copy()
    c.update(b)
    return c

a = {"x": 1, "y": 2}
b = {"y": 3, "z": 4}
print(merge_two_dicts(a, b))  # {'x': 1, 'y': 3, 'z': 4}

20. Convert two lists to a dictionary

def to_dictionary(keys, values):
    return dict(zip(keys, values))

keys = ["a", "b", "c"]
values = [2, 3, 4]
print(to_dictionary(keys, values))  # {'a': 2, 'b': 3, 'c': 4}

21. Enumerate dictionary keys

lst = ["a", "b", "c", "d"]
for index, element in enumerate(lst):
    print("Value", element, "Index", index)

22. Measure execution time

import time
start_time = time.time()
# ... code to measure ...
end_time = time.time()
print("Time:", end_time - start_time)

23. Try/else example

try:
    2*3
except TypeError:
    print("An exception was raised")
else:
    print("Thank God, no exceptions were raised.")

24. Most frequent element in a list

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

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

25. Palindrome check

def palindrome(string):
    from re import sub
    s = sub(r"\W_", "", string.lower())
    return s == s[::-1]

print(palindrome("taco cat"))  # True

26. Calculator without if‑else

import operator
action = {
    "+": operator.add,
    "-": operator.sub,
    "/": operator.truediv,
    "*": operator.mul,
    "**": pow,
}
print(action["-"](50, 25))  # 25

27. Shuffle a list (Fisher‑Yates)

from copy import deepcopy
from random import randint

def shuffle(lst):
    temp_lst = deepcopy(lst)
    m = len(temp_lst)
    while m:
        m -= 1
        i = randint(0, m)
        temp_lst[m], temp_lst[i] = temp_lst[i], temp_lst[m]
    return temp_lst

foo = [1,2,3]
print(shuffle(foo))  # e.g., [2,3,1]

28. List flattening (like JavaScript spread)

def spread(arg):
    ret = []
    for i in arg:
        if isinstance(i, list):
            ret.extend(i)
        else:
            ret.append(i)
    return ret

print(spread([1,2,3,[4,5,6],[7],8,9]))  # [1,2,3,4,5,6,7,8,9]

29. Swap two variables

def swap(a, b):
    return b, a

a, b = -1, 14
print(swap(a, b))  # (14, -1)

30. Get default value for missing dictionary key

d = {"a": 1, "b": 2}
print(d.get("c", 3))  # 3

The snippets are sourced from the GitHub project 30‑seconds‑of‑knowledge , which contains many more useful examples across Python and other languages.