Articles from Patrick Loeber

"I'm a passionate Software Engineer who loves Machine Learning, Computer Vision, and Data Science."

123 Articles from Patrick.

How to split a List into equally sized chunks in Python

Learn different ways you can use to split a List into equally sized chunks in Python.

Learn different ways you can use to split a List into equally sized chunks in Python.

The following methods can be used to batch data from an iterable into lists or tuples of equal length n:

How to delete a key from a dictionary in Python

Learn how you can remove a key from a dictionary in Python.

This article shows how you can remove a key from a dictionary in Python.

To delete a key, you can use two options:

Using del my_dict['key']
Using my_dict.pop('key', None)

Let's look at both options in detail:

How to convert a Google Colab to Markdown

Learn how to you can convert a Google Colab to a Markdown file and download it.

Learn how to you can convert a Google Colab to a Markdown file and download it.

Colab only provides the options to download the file either as .ipynb or as .py file. But you can use this workaround to also download it as markdown file.

LangChain Tutorial in Python - Crash Course

In this LangChain Crash Course you will learn how to build applications powered by large language models.

LangChain is a framework for developing applications powered by language models. In this LangChain Crash Course you will learn how to build applications powered by large language models. We go over all important features of this framework.

Overview:¶

Installation
LLMs
Prompt Templates
Chains
Agents and Tools
Memory
Document Loaders
Indexes

How to write your own context manager in Python

Learn how to write your own context manager in Python with the contextlib.contextmanager decorator

Learn how to write your own contextmanager in Python with the contextlib.contextmanager decorator.

How to easily remove the background of images in Python

Learn how you can easily remove the background of images in Python.

Learn how you can easily remove the background of images in Python.

For this, we use the Open Source tool rembg and only need a few lines of code.

How to work with the Notion API in Python

Guide on how to work with the Notion API in Python and automate database editing.

Learn how to work with the Notion API in Python. In this guide we go over:

How to set up the Notion API
How to set up the Python code
How to create database entries
How to query the database
How to update database entries
And how to delete entries.

How to measure the elapsed time in Python

Learn how you can measure elapsed time in Python with different methods.

Learn how you can measure elapsed time in Python.

We will look at those different methods:

Use time.time()
Use timeit.default_timer()
Use timeit from the command line
Use timeit in code
Use timeit in Jupyer Notebook Cells
Use a decorator

How to copy a List in Python without side effects

Learn different ways to copy/clone a List in Python so that it doesn't change unexpectedly.

Learn different ways to copy/clone a List in Python so that it doesn't change unexpectedly.

When copying Lists (and other collection data types) in Python, we have to be careful.

When we simply use the copy assignment we only copy the reference to the List:

a = [1, 2, 3]

b = a

Both objects point to the same memory location, so changing one List also affects the other one!

b.append(4)

print(b) # [1, 2, 3, 4]
print(a) # [1, 2, 3, 4]

So how do we properly clone a List in Python?

How to check if a List is empty in Python

Learn the easiest and most pythonic way to check if a List is empty in Python.

Learn the easiest and most pythonic way to check if a List is empty in Python.

Let's say we have an empty List:

my_list = []

How to sort a dictionary by values in Python

Learn how you can sort a dictionary by values in Python.

Learn how you can sort a dictionary in Python.

How to schedule Python scripts with GitHub Actions

Learn how you can schedule and run Python scripts for free using GitHub Actions and cron syntax.

Learn how you can schedule and run Python scripts for free using GitHub Actions and cron syntax.

I created a python-github-action-template you can use to get started quickly. It demonstrates the following:

How to schedule Python scripts with a GitHub Action
How to use dependencies from a requirements.txt
How to use secret environment variables (e.g. for an API Token)
How to add the changes to the repository

The example script from the template runs once a week to get the weather from an API, logs the weather to a file, and commit and pushes the updated log file to the repository.

If you want to know how everything works, read on.

How to create a constant in Python

Learn how to create constant, read-only variables in Python.

Learn how to create constant, read-only variables in Python.

Many other languages like C++ or Java have keywords to declare constants:

C++

const int maxValue = 99;

Java

public static final int MAX_VALUE = 99;

But what about a constant specifier in Python?

Best hosting platforms for Python applications and Python scripts

In this article I present you 14 different options where you can host your Python apps and Python scripts!

In this article I present you 14 different options where you can host your Python apps and Python scripts!

This list is not based on any rating, but rather, let’s divide it into 3 categories:

1-5: One-click solutions (Cloud/Infrastructure platforms as a service)
5-10: Cloud Server (Private Linux machine / VPS)
11-14: Hidden champs you might not have on your radar

Let’s have a look at them!

How to reverse a String in Python

Learn how to reverse Strings in Python using slicing.

This article explains how to reverse a String in Python using slicing.

There is no built-in string.reverse() function. However, there is another easy solution.

How to debug Python apps inside a Docker Container with VS Code

Learn how you can use a debugger in VS Code inside a Docker Container to debug Python apps.

This article shows how you can can use a debugger in VS Code to debug Python apps inside a Docker Container.

6 Tips To Write Better For Loops in Python

6 Tips To Write Better For Loops in Python

In this tutorial we'll have a look at 6 tips to write better For-Loops in Python. These tips include easy refactoring methods that you can apply right away in your code.

1) Don't use loops at all¶

If possible, try to avoid loops and use built-in methods instead.

10 Python One Liner You Must Know

Ten beginner-friendly Python one liner that are fun to know and easy to use.

Here are 10 beginner-friendly Python one liner you should know.

Careful

A one-liner does not alwasy mean it's the best choice. You should always prefer readability over shortening your code! However, these one-liners are fun to know and some of them are pretty useful.

How to apply image thresholding in Python with NumPy

Learn how to apply a threshold to images in Python with numpy and Pillow.

Learn how to apply a threshold to images in Python with numpy and Pillow.

This snippet loads an image, applies a threshold, and then saves a new binarized image with only black and white pixels.

15 Best AI Newsletters

A curated list of 15 newsletters to stay informed on the latest AI news and research.

The field of AI is moving incredibly fast, and it’s almost impossible to stay up to date with all the new inventions. In my opinion, subscribing to a few well-written newsletters is the best way to keep up with the most important trends.

So here’s a curated list of 15 newsletters to stay informed on the latest AI news and research.

Last updated: November, 2023

File Organizing with Python

Learn how to automate file organization in Python.

How to rename files in Python

Learn different ways to rename files in Python using the os and pathlib modules.

Learn different ways to rename files in Python using the os and pathlib modules.

Tip - Use the round() function with negative arguments

You can use the round() function with negative arguments to round it to the nearest 10, 100, 1000, and so on.

The round function rounds a number to the given precision in decimal digits:

Tip - The print function can take additional arguments

Learn what additional arguments you can use for the print function.

We all know the print function in Python

Tip - Find the longest String in a List in Python using the max() function

Learn how to easily find the longest String in a List in Python using the max() function.

The most efficient way to find the longest String in a List in Python is by using the max function with key=len:

Tip - How to loop over multiple Lists in Python with the zip function

Learn how to loop over multiple Lists in Python with the zip function.

Don't use a for loop like this for multiple Lists in Python:

Create a Task Tracker App for the Terminal with Python (Rich, Typer, Sqlite3)

In this Python Tutorial we learn how to build a terminal application (CLI app) to manage our tasks and todos.

How To Analyze Apple Health Data With Python

In this article we learn how to analyze Apple Health Data with Python.

In this article we learn how to analyze Apple Health Data with Python. We learn how to

What are *args and **kwargs in Python

Understand the purpose and usage of args and kwargs in Python functions.

The concept of args and kwargs is a common use case found in function arguments in Python.

31 essential String methods in Python you should know

In this article we learn about the most essential built-in string methods.

Quick Python Refactoring Tips (Part 2)

8 quick Python refactoring tips for cleaner and more Pythonic code.

How to ask the user for input until they give a valid response in Python

A clean way to ask the user for input and catch invalid inputs.

How to ask the user for input until they give a valid response in Python. Here's one clean way:

Master Pattern Matching In Python 3.10 | All Options |

Master the new Pattern Matching Feature in Python 3.10. We have a look at all the different code syntax options.

Create a Note Taking App in Python with Speech Recognition and the Notion API

In this Python Tutorial we create a note taking app with speech recognition and the Notion API.

Python Automation Projects With Machine Learning

This article shows and explains the most important new features in Python 3.10.

New Features In Python 3.10 You Should Know

This article shows and explains the most important new features in Python 3.10.

5 Python Pitfalls that can save you HOURS of debugging!

Knowing this can save you HOURS of debugging! (5 Python Pitfalls)

What is the difference between append and extend for Python Lists?

This article shows the difference between append() and extend() for Python Lists.

This article shows the difference between append() and extend() for Python Lists.

10 Python Basics You Should Know!

10 Must Know Python Basics and More Tips And Tricks.

How to concatenate two Lists in Python

Learn different ways to concatenate two lists or other iterables in Python.

This article shows different ways to concatenate two lists or other iterables in Python.

Difference between str and repr in Python

Learn what's the difference between the __str__ and __repr__ methods in Python.

Learn what's the difference between the __str__ and __repr__ methods in Python.

Difference between @classmethod, @staticmethod, and instance methods in Python.

Learn what's the difference between a class method, a static method, and an instance method in Python.

Learn what's the difference between a class method, a static method, and an instance method in Python.

How to pad zeros to a String in Python

This article shows how to pad a numeric string with zeroes to the left such that the string has a specific length.

This article shows how to pad a numeric string with zeroes to the left such that the string has a specific length.

How to create a nested directory in Python

This article shows how a directory and all missing parents of this directory can be created in Python.

This article shows how a directory and all missing parents of this directory can be created in Python.

How to merge two Dictionaries in Python

This article shows different ways to merge two Dictionaries in Python.

This article shows different ways to merge two Dictionaries in Python.

How to execute a Program or System Command from Python

Learn how to run a system command from Python and how to execute another program.

This article shows how to run a system command from Python and how to execute another program.

How to check if a String contains a Substring in Python

Learn how to check if a String contains a Substring in Python and how to get the position.

Learn how to check if a string contains a substring in Python and how to get the position of the substring.

How to find the index of an item in a List in Python

Learn how the index of an item in Python Lists can be found.

To find the index of an item in Python lists, you can simply use my_list.index():

How to access the index in a for loop in Python

Find out how to access the index in for loops in Python.

Find out how to access the index in a for loop in Python.

How to check if a file or directory exists in Python

This article presents different ways how to check if a file or a directory exists in Python.

When you want to open a file and the corresponding file or directory of the given path does not exists, Python raises an Exception. You should address this, otherwise your code will crash.

This article presents different ways how to check if a file or a directory exists in Python, and how to open a file safely.

Use a `try-except` block¶

First of all, instead of checking if the file exists, it’s perfectly fine to directly open it and wrap everything in a try-except block. This strategy is also known as EAFP (Easier to ask for forgiveness than permission) and is a perfectly accepted Python coding style.

 try:
    f = open("filename.txt")
 except FileNotFoundError:
     # doesn’t exist
 else:
     # exists

How to remove elements in a Python List while looping

Learn how to remove elements in a List in Python while looping over it. There are a few pitfalls to avoid.

A very common task is to iterate over a list and remove some items based on a condition. This article shows the different ways how to accomplish this, and also shows some common pitfalls to avoid.

Let's say we need to modify the list a and have to remove all items that are not even. We have this little helper function to determine whether a number is even or not.

a = [1, 2, 2, 3, 4]

<p hidden>#more</p>

def even(x):
    return x % 2 == 0

Option 1: Create a new list containing only the elements you don't want to remove¶

1a) Normal List comprehension¶

Use list comprehension to create a new list containing only the elements you don't want to remove, and assign it back to a.

a = [x for x in a if not even(x)]
# --> a = [1, 3]

You can learn more about list compehension in this tutorial.

1b) List comprehension by assigning to the slice `a[:]`¶

The above code created a new variable a. We can also mutate the existing list in-place by assigning to the slice a[:]. This approach is more efficient and could be useful if there are other references to a that need to reflect the changes.

a[:] = [x for x in a if not even(x)]
# --> a = [1, 3]

1c) Use `itertools.filterfalse()`¶

The itertools module provides various functions for very efficient looping and also offers a method to filter items:

from itertools import filterfalse
a[:] = filterfalse(even, a)
# --> a = [1, 3]

Option 2: Loop over a copy¶

If you really want to keep the for-loop syntax, then you need to iterate over a copy of the list (A copy is simply created by using a[:]). Now you can remove items from the original list if the condition is true.

for item in a[:]:
    if even(item):
        a.remove(item)
# --> a = [1, 3]

What NOT to do¶

Do not loop over the same list and modify it while iterating!

This is the same code as above except that here we don't loop over a copy. Removing an item will shift all following items one place to the left, thus in the next iteration one item will be skipped. This can lead to incorrect results.

for item in a:
    if even(item):
        a.remove(item)
# --> a = [1, 2, 3] !!!

Also, never modify the index while looping over the list!

This is incorrect because changing i inside the loop will NOT affect the value of i in the next iteration. This example also produces unwanted effects and even lead to IndexErrors like here.

for i in range(len(a)):
    if even(a[i]):
        del a[i]
        i -= 1
# --> IndexError: list index out of range

What does if name == "main" do?

It's good practice to apply this in your scripts. Find out why and how this works.

It is boilerplate code that protects users from accidentally invoking a script when they didn’t intend to, and it’s good practice apply it. This makes a difference for these two use cases:

The Best FREE Machine Learning Crash Courses

In this post I share my favorite free Machine Learning Crash Courses.

How to write while loops in Python

A while loop is used for iterating over a sequence. This artice shows how to use while loops.

A while loop in Python is used to repeatedly execute code as long as the given condition is true.

How to write for loops in Python

A for loop is used for iterating over a sequence. This artice shows how to use for loops.

A for loop is used for iterating over a sequence. This can be for example a list, a tuple, a dictionary, a set, a string, or a range object.

Quick Python Refactoring Tips

8 quick Python refactoring tips for cleaner and more Pythonic code.

Async Views in Django 3.1

Learn about new Django async features like async views, middleware, and tests.

Django 3.1. finally supports async views, middleware, and tests. This article gives an overview of the new asynchronous features, why it’s important, and how you can use it with little effort to speed up your application. Along the way we build a small demo application demonstrating how to implement the async functionalities.

Build A Machine Learning iOS App | PyTorch Mobile Deployment

Learn how to deploy PyTorch models on iOS devices with Torchscript.

HuggingFace Crash Course

Learn everything to get started with Huggingface and the Transformers library.

10 Deep Learning Projects With Datasets (Beginner & Advanced)

In this video I show you 10 deep learning projects from beginner to advanced that you can do with TensorFlow or PyTorch.

How To Deploy ML Models With Google Cloud Run

Learn how to deploy Machine Learning models with Google Cloud Run.

MongoDB Crash Course With Python

In this MongoDB Crash Course with Python you will learn everything you need to get started.

Why I Don't Care About Code Formatting In Python | Black Tutorial

In this tutorial I explain why I don't care about code formatting while writing Python code.

Build A Machine Learning Web App From Scratch

Build a Machine Learning web application from scratch in Python with Streamlit.

Beautiful Terminal Styling in Python With Rich

In this Python Tutorial I show you how you can create beautiful terminal styling with Rich. Rich is a Python library for rich text and beautiful formatting in the terminal.

How To Hack Neural Networks!

In this Tutorial I show you how easily Neural Networks can be hacked, and what you should do to protect against this.

Should You Use FOR Or WHILE Loop In Python?

In this Python Tutorial we learn if the for loop or the while loop is faster in Python, and I show 3 better solutions instead of these loops.

Learn NumPy In 30 Minutes

Learn all essential numpy functions in this tutorial.

Quick Data Analysis In Python Using Mito

In this Python Tutorial you will learn how you can efficiently work with spreadsheets in order to analyze and edit your data.

Autoencoder In PyTorch - Theory & Implementation

In this Deep Learning Tutorial we learn how Autoencoders work and how we can implement them in PyTorch.

How To Scrape Reddit & Automatically Label Data For NLP Projects | Reddit API Tutorial

In this tutorial I show you how to scrape reddit with the reddit API and automatically label the data for NLP projects.

How To Build A Photo Sharing Site With Django

In this video you will learn how to build a photo sharing web app using Django.

PyTorch Time Sequence Prediction With LSTM - Forecasting Tutorial

In this Python Tutorial we do time sequence prediction in PyTorch using LSTMCells.

Create Conversational AI Applications With NVIDIA Jarvis

I show you an overview of the NVIDIA Jarvis framework for conversational AI and how to get started with it.

Create A Chatbot GUI Application With Tkinter

In this Python Tutorial we build a GUI application with Tkinter for a chatbot.

Build A Stock Prediction Web App In Python

In this tutorial we build a stock prediction web app in Python using streamlit, Yahoo finance, and Facebook Prophet.

Machine Learning From Scratch in Python - Full Course [FREE]

In this course we implement the most popular Machine Learning algorithms from scratch using only Python and NumPy.

Awesome Python Automation Ideas

In this Tutorial I share quick Python Automation Ideas that you can use everyday to simplify your life.

How To Edit Videos With Python

In this tutorial, I show you how I edit my videos using Python and MoviePy

How To Schedule Python Scripts As Cron Jobs With Crontab (Mac/Linux)

Learn about cron jobs and how to schedule commands and Python scripts in the terminal via crontab (for Linux and Mac)

Build A Website Blocker With Python - Task Automation Tutorial

Learn how to create a website blocker that automates the site blocking for us and helps us to be more productive.

How To Setup Jupyter Notebook In Conda Environment And Install Kernel

How to setup Jupyter Notebook in a conda environment and then install the kernel

Whenever I setup a new conda environment and want to use a jupyter notebook with the correct Kernel for this environment, I find myself googling this over and over again. So I finally decided to list the necessary commands here.

Teach AI To Play Snake - Practical Reinforcement Learning With PyTorch And Pygame

In this Python Reinforcement Learning Tutorial series we teach an AI to play Snake! We build everything from scratch using Pygame and PyTorch.

Python Snake Game With Pygame - Create Your First Pygame Application

Implement the famous Snake game in this beginner tutorial and learn how to get started with pygame.

PyTorch LR Scheduler - Adjust The Learning Rate For Better Results

In this PyTorch Tutorial we learn how to use a Learning Rate (LR) Scheduler to adjust the LR during training.

Docker Tutorial For Beginners - How To Containerize Python Applications

In this Docker Tutorial I show how to get started with Docker for your Python Scripts and Python Web Apps.

Object Oriented Programming (OOP) In Python - Beginner Crash Course

In this Beginner Object Oriented Programming (OOP) Tutorial I will be covering all the fundamentals about classes, objects, and inheritance in Python.

FastAPI Introduction - Build Your First Web App

In this Tutorial we have a look at some of its key features and then we build our first web application with it.

5 Machine Learning BEGINNER Projects (+ Datasets & Solutions)

I this tutorial I share 5 Beginner Machine Learning projects with you and give you tips how to solve all of them.

Build A PyTorch Style Transfer Web App With Streamlit

In this tutorial we build an interactive deep learning app with Streamlit and PyTorch to apply style transfer.

How to use the Python Debugger using the breakpoint()

Learn how to use the Python Debugger using the breakpoint() function in this Tutorial.

How to use the interactive mode in Python.

Learn how to use the interactive mode in Python.

Support Me On Patreon

Support me on Patreon and get access to exclusive contents.

I created a Patreon page for all that want to support my work. You get exclusive content:

PyTorch Tutorial - RNN & LSTM & GRU - Recurrent Neural Nets

Implement a Recurrent Neural Net (RNN) in PyTorch! Learn how we can use the nn.RNN module and work with an input sequence.

freeCodeCamp.org Released My Intermediate Python Course

freeCodeCamp.org released my 6-hour intermediate Python course.

I feel proud and honored to announce that I partnered up with freeCodeCamp.org!

PyTorch RNN Tutorial - Name Classification Using A Recurrent Neural Net

Implement a Recurrent Neural Net (RNN) from scratch in PyTorch! I briefly explain the theory and different kinds of applications of RNNs. Then we implement a RNN to do name classification.

PyTorch Lightning Tutorial - Lightweight PyTorch Wrapper For ML Researchers

In this Tutorial we learn about this framework and how we can convert our PyTorch code to a Lightning code.

My Minimal VS Code Setup for Python - 5 Visual Studio Code Extensions

I show you my minimal Visual Studio Code Setup for Python Programming. I use only 5 Extensions. It's simple but allows me to be really productive.

NumPy Crash Course 2020 - Complete Tutorial

Learn NumPy in this complete Crash Course! I show you all the essential functions of NumPy and some tricks and useful methods.

Create & Deploy A Deep Learning App - PyTorch Model Deployment With Flask & Heroku

Create and Deploy your first Deep Learning app! In this PyTorch tutorial we learn how to deploy our PyTorch model with Flask and Heroku.

Snake Game In Python - Python Beginner Tutorial

Implement the famous Snake game in this beginner tutorial using the curses module!

11 Tips And Tricks To Write Better Python Code

I show 11 Tips and Tricks to Write Better Python code! I show a lot of best practices that improve your code by making your code much cleaner and more Pythonic.

Python Flask Beginner Tutorial - Todo App

Learn how to write a TODO App with Flask in this Crash Course.

Chat Bot With PyTorch - NLP And Deep Learning

In this tutorial we build a simple chatbot in PyTorch. I will also provide an introduction to some basic Natural Language Processing (NLP) techniques.

Build A Beautiful Machine Learning Web App With Streamlit And Scikit-learn

In this tutorial we build an interactive machine learning app with Streamlit and Scikit-learn to explore different datasets and classifier.

Website Rebuild With Publish (Static Site Generator)

I've rebuilt this site using Publish (Static Site Generator) by John Sundell. The website contains now all of my tutorials and videos.

Update Nov 26, 2022

Articles from Patrick Loeber

Overview:¶

1) Don't use loops at all¶

Use a try-except block¶

Option 1: Create a new list containing only the elements you don't want to remove¶

1a) Normal List comprehension¶

1b) List comprehension by assigning to the slice a[:]¶

1c) Use itertools.filterfalse()¶

Option 2: Loop over a copy¶

What NOT to do¶

Use a `try-except` block¶

1b) List comprehension by assigning to the slice `a[:]`¶

1c) Use `itertools.filterfalse()`¶