Common Python Tricks and Best Practices

In this article we discuss frequently used Python tricks that the author has collected from daily work and wants to share.

Handling multiple user inputs

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

Better approach using tuple unpacking:

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

Processing multiple conditional statements

Use all() for multiple AND conditions and any() for multiple OR conditions.

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

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

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

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

Determining odd or even numbers

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

Swapping variables

# bad practice
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 "")
name and print(name)
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 repeated 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]

Using *args to pass multiple arguments

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)

Creating a dictionary from two lists using zip

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

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 and reverse=True for descending order:

from operator import itemgetter
sorted_d = dict(sorted(d.items(), key=itemgetter(1), reverse=True))

Reversing a list

# slice method (creates new list)
new_list = mylist[::-1]
# reverse() method (in‑place)
mylist.reverse()

Performance test shows reverse() is faster than slicing.

Pretty‑printing 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)

Using pprint makes dictionary output easier to read.