Common Python Tricks and Best Practices

In this article we discuss some of the most frequently used Python tricks. Most of these tricks are simple tricks I have used in daily work and I think good things should be shared with everyone.

Handling multiple user inputs

Sometimes we need to get several inputs from the user. A common (but inefficient) way is:

# bad practice
n1 = input("enter a number : ")
n2 = input("enter a number : ")
n3 = input("enter a number : ")
print(n1, n2, n3)

A better approach is to read a single line and split it:

# good practice
n1, n2, n3 = input("enter a number : ").split()
print(n1, n2, n3)

Handling multiple condition statements

When we need to check several conditions we can use all() for logical AND and any() for logical OR. Example with all():

# bad practice
size = "lg"
color = "blue"
price = 50
if size == "lg" and color == "blue" and price < 100:
    print("Yes, I want to buy the product.")

Improved version using a list of conditions:

# good practice
conditions = [
    size == "lg",
    color == "blue",
    price < 100,
]
if all(conditions):
    print("Yes, I want to buy the product.")

Similar improvement for any():

# bad practice
if size == "lg" or color == "blue" or price < 100:
    print("Yes, I want to buy the product.")

# good practice
conditions = [
    size == "lg",
    color == "blue",
    price < 100,
]
if any(conditions):
    print("Yes, I want to buy the product.")

Determining odd or even numbers

print('odd' if int(input('Enter a number: ')) % 2 else 'even')

Swapping variables

# bad practice
v1 = 100
v2 = 200
temp = v1
v1 = v2
v2 = temp

# good practice
v1, v2 = v2, v1

Checking if a string is a palindrome

v1 = "madam"  # palindrome
v2 = "master"  # not a palindrome
print(v1.find(v1[::-1]) == 0)  # True
print(v2.find(v2[::-1]) == 0)  # False

Using inline if statements

# bad practice
if name:
    print(name)
if name and age > 18:
    print("user is verified")

# better approach
print(name if name else "")
age > 18 and name and print("user is verified")

Removing duplicate elements from a list

lst = [1, 2, 3, 4, 3, 4, 4, 5, 6, 3, 1, 6, 7, 9, 4, 0]
unique_lst = list(set(lst))
print(unique_lst)

Finding the most frequent element in a list

lst = [1, 2, 3, 4, 3, 4, 4, 5, 6, 3, 1, 6, 7, 9, 4, 0]
most_repeated_item = max(lst, key=lst.count)
print(most_repeated_item)

List comprehensions

numbers = [1,2,3,4,5,6,7]
evens = [x for x in numbers if x % 2 == 0]
odds = [y for y in numbers if y not in evens]
cities = ['London', 'Dublin', 'Oslo']

def visit(city):
    print("Welcome to " + city)

for city in cities:
    visit(city)

Using *args to pass multiple arguments

def sum_of_squares(n1, n2):
    return n1**2 + n2**2
print(sum_of_squares(2,3))  # 13

# dynamic version

def sum_of_squares(*args):
    return sum(item**2 for item in args)
print(sum_of_squares(2,3,4))
print(sum_of_squares(2,3,4,5,6))

Iterating with index using enumerate

lst = ["blue", "lightblue", "pink", "orange", "red"]
for idx, item in enumerate(lst):
    print(idx, item)

Joining list elements into a string

names = ["john", "sara", "jim", "rock"]
print(", ".join(names))

Merging dictionaries

d1 = {"v1": 22, "v2": 33}
d2 = {"v2": 44, "v3": 55}
d3 = {**d1, **d2}
print(d3)  # {'v1': 22, 'v2': 44, 'v3': 55}

Creating a dictionary from two lists

keys = ['a', 'b', 'c']
vals = [1, 2, 3]
zipped = dict(zip(keys, vals))
print(zipped)

Sorting a dictionary by value

d = {"v1": 80, "v2": 20, "v3": 40, "v4": 20, "v5": 10}
sorted_d = dict(sorted(d.items(), key=lambda item: item[1]))
print(sorted_d)

# using itemgetter
from operator import itemgetter
sorted_d = dict(sorted(d.items(), key=itemgetter(1)))
print(sorted_d)

# descending order
sorted_d = dict(sorted(d.items(), key=itemgetter(1), reverse=True))
print(sorted_d)

Pretty‑printing complex data structures

from pprint import pprint

data = {
    "name": "john deo",
    "age": "22",
    "address": {
        "country": "canada",
        "state": "an state of canada :)",
        "address": "street st.34 north 12"
    },
    "attr": {"verified": True, "emailaddress": True}
}
print(data)
pprint(data)

Reversing a list

# using slicing
mylist[::-1]

# using reverse()
mylist.reverse()

# timing example (slice: 15.6 µs, reverse(): 10.7 µs)

Overall, these snippets demonstrate concise, readable, and efficient ways to perform common Python tasks.