Code Smarter, Not Harder: 10 Python Efficiency Hacks

Huzaifa Zahoor
5 min readApr 16, 2023

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In this article, we’ll explore 10 tips and tricks that can help you write more efficient Python code, from optimizing your data structures to using built-in functions and libraries. Whether you’re a beginner or an experienced developer, these tips will help you write code that runs faster, uses less memory, and makes your life easier. So, let’s dive in and discover how to take your Python code to the next level!

Streamline Your Python Code with These 10 Efficiency Tips

Python is one of the most popular programming languages used today, thanks to its simplicity, readability, and versatility. However, writing efficient Python code can be a challenge, especially if you’re new to the language.

10 Tips to Write More Efficient Python Code

Here are the top 10 tips for writing more efficient Python code regarding performance and speed.

Use List Comprehension

List comprehension is a concise and efficient way to create a new list from an existing one. It is faster and more readable than using a for loop. For example, instead of using a for loop to create a list of even numbers, you can use list comprehension like this:

# Create a list of even numbers using a for loop
even_numbers = []
for i in range(10):
if i % 2 == 0:
even_numbers.append(i)

# Create a list of even numbers using list comprehension
even_numbers = [i for i in range(10) if i % 2 == 0]

Avoid Using Global Variables

Global variables can cause unexpected behavior in your code and make it harder to debug. It’s best to avoid them as much as possible and use local variables instead.

# Bad example using global variables
my_variable = 10

def my_function():
global my_variable
my_variable += 1

# Good example using local variables
def my_function():
my_variable = 10
my_variable += 1

Use Generators

Generators are a memory-efficient way to iterate over large datasets. They allow you to generate values on-the-fly, rather than storing them all in memory at once. This can be a huge performance boost for your code.

Sometimes you might need to divide a large list into smaller chunks for processing. Using a for loop to do this can be inefficient and may not scale well. Instead, you can use the yield keyword to create a generator function that returns chunks of a given size.

Here’s an example of how you can divide a list into chunks using “yield”:

def chunk_list(lst, chunk_size):
"""Divide a list into chunks of size chunk_size"""
for i in range(0, len(lst), chunk_size):
yield lst[i:i+chunk_size]

my_list = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

# Divide the list into chunks of size 3
for chunk in chunk_list(my_list, 3):
print(chunk)

This will output:

[1, 2, 3]
[4, 5, 6]
[7, 8, 9]
[10]

Use the “in” Keyword

The in keyword is a powerful tool for working with collections like lists, tuples, and dictionaries. It allows you to check if an element is present in a collection without having to loop over the entire collection.

# Check if an element is present in a list using a for loop
my_list = [1, 2, 3, 4, 5]
is_present = False
for element in my_list:
if element == 3:
is_present = True

# Check if an element is present in a list using "in" keyword
my_list = [1, 2, 3, 4, 5]
is_present = 3 in my_list

Use the “with" Statement

The with statement is a handy way to manage resources like files, sockets, and database connections. It ensures that the resource is properly closed when you’re done with it, even if an error occurs.

# Open a file using a try/finally block
f = open("my_file.txt", "r")
try:
contents = f.read()
finally:
f.close()

# Open a file using "with" statement
with open("my_file.txt", "r") as f:
contents = f.read()

Use the “enumerate” Function

The enumerate function allows you to iterate over a collection while also keeping track of the index of each element. This can be useful for creating dictionaries, or for printing out messages that include the position of each item in a list.

# Iterate over a list using a for loop and index variable
my_list = ["apple", "banana", "cherry"]
for index in range(len(my_list)):
print(index, my_list[index])

# Iterate over a list using "enumerate" function
my_list = ["apple", "banana", "cherry"]
for index, item in enumerate(my_list):
print(index, item)

Use the “zip” Function

The zip function allows you to combine two or more lists into a single list of tuples. This can be useful for iterating over multiple lists at once, or for creating dictionaries where one list contains keys, and another contains values.

# Combine two lists using a for loop and zip function
list_1 = [1, 2, 3]
list_2 = ["a", "b", "c"]
result = []
for i in range(len(list_1)):
result.append((list_1[i], list_2[i]))

# Combine two lists using "zip" function
list_1 = [1, 2, 3]
list_2 = ["a", "b", "c"]
result = list(zip(list_1, list_2))

Use Default Arguments

Default arguments can be used to provide a default value for a function argument if no value is provided by the caller. This can make your code more readable and reduce the amount of boilerplate code you need to write.

# Function without default argument
def my_function(x, y):
if x is None:
x = 0
if y is None:
y = 0
return x + y

# Function with default argument
def my_function(x=0, y=0):
return x + y

Use the “itertools” Module

The itertools module provides a collection of functions for working with iterators. It includes functions like chain for combining multiple iterators into a single one, cycle for repeating an iterator indefinitely, and groupby for grouping items in an iterator by a key function.

# Create a list of unique items in a list using a for loop
my_list = ["apple", "banana", "banana", "cherry", "cherry"]
unique_items = []
for item in my_list:
if item not in unique_items:
unique_items.append(item)

# Create a list of unique items in a list using "itertools" module
import itertools
my_list = ["apple", "banana", "banana", "cherry", "cherry"]
unique_items = list(itertools.groupby(sorted(my_list)))
unique_items = [k for k, g in unique_items]

Use Profiling Tools

Profiling tools like cProfile and PyCharm’s profiler can help you identify performance bottlenecks in your code. They allow you to see how much time your code spends in each function and can help you optimize your code for speed.

# Time a function using a for loop
import time

def my_function():
time.sleep(1)

start_time = time.time()
my_function()
end_time = time.time()
print(end_time - start_time)

# Time a function using "timeit" module
import timeit

def my_function():
time.sleep(1)

execution_time = timeit.timeit(my_function, number=1)
print(execution_time)

Conclusion

In conclusion, by incorporating these top 10 daily basis codes into your Python code, you can significantly improve its efficiency and performance. Remember to avoid using global variables, use generators, and take advantage of powerful Python functions like list comprehension, with statement, zip function, and more. And don’t forget to use profiling tools to identify and optimize performance bottlenecks in your code.

If you enjoyed learning about efficient Python coding practices, you may also be interested in our article on building scalable and maintainable Django applications. Check it out here!

Looking to improve the quality of your Python code even further? Check out our guide on Improving Code Quality with Flake8 and Black. You’ll learn how to use these powerful tools to catch errors, maintain a consistent style, and enhance the overall quality of your code.

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Huzaifa Zahoor

Huzaifa Zahoor is a Python developer and data engineer with over 3 years of experience in building web applications for the stock market.