Python Tips: Variable Swapping, Comprehensions, Counter, JSON Pretty‑Print, FizzBuzz, and More

This guide gathers a series of useful Python tricks that illustrate concise syntax and built‑in library features.

Variable swapping can be done in a single line without a temporary variable:

>> a = 3
>>> b = 6
>>> a, b = b, a
>>> print(a)  # 6
>>> print(b)  # 3

Dictionary and set comprehensions provide compact ways to build new collections:

some_list = [1, 2, 3, 4, 5, 2, 5, 1, 4, 8]
even_set = {x for x in some_list if x % 2 == 0}

d = {x: x % 2 == 0 for x in range(1, 11)}

The collections.Counter class simplifies counting occurrences:

from collections import Counter
c = Counter('hello world')
print(c.most_common(2))  # [('l', 3), ('o', 2)]

Pretty‑printing JSON improves readability, especially for large structures:

import json
print(json.dumps(data))
print(json.dumps(data, indent=2))

A compact FizzBuzz solution can be written using slicing:

for x in range(1, 101):
    print('fizz'[x%3*len('fizz'):] + 'buzz'[x%5*len('buzz'):] or x)

Inline conditional expressions allow one‑line decisions:

print('Hello' if True else 'World')

List concatenation and slicing examples demonstrate quick data manipulation:

nfc = ['Packers', '49ers']
af c = ['Ravens', 'Patriots']
print(nfc + afc)          # ['Packers', '49ers', 'Ravens', 'Patriots']
print(x[:3])              # first three items
print(x[1:5])             # middle four items
print(x[::2])             # odd‑indexed items

Using dict.get avoids explicit try/except when a key may be missing:

is_admin = data.get('admin', False)

The itertools module can generate combinations efficiently:

from itertools import combinations
for game in combinations(teams, 2):
    print(game)

Because True and False are just names, they can be reassigned (though not recommended):

False = True
if False:
    print('Hello')
else:
    print('World')  # prints Hello