Is __init__.py not required for packages in Python 3.3+

📝Is init.py not required for packages in Python 3.3+?🤔

Hey there! Today, we're diving into the world of Python packages and discussing whether the __init__.py file is still required in Python 3.3+ 🐍💼

You might have come across some confusion when importing modules within a package or noticed changes from Python 2.7. Let's explore this and find out what's going on! 💡🔍

First, let me give you a quick overview of the package structure in question:

/home/wujek/Playground
└── a
    └── b
        └── module.py

Inside module.py, we have a simple class called Foo with an __init__ method. Nothing fancy, just a straightforward example. 😎👨‍💻

Now, let's go through the examples you provided. When you import a.b.module from ~/Playground, everything works perfectly fine, without the need for __init__.py:

~/Playground $ python3
>>> import a.b.module
>>> a.b.module.Foo()
initializing Foo
<a.b.module.Foo object at 0x100a8f0b8>

Similarly, when in the parent folder home, importing with PYTHONPATH=Playground still works smoothly:

~ $ PYTHONPATH=Playground python3
>>> import a.b.module
>>> a.b.module.Foo()
initializing Foo
<a.b.module.Foo object at 0x10a5fee10>

But why does this work? Has something changed between Python 2.7 and Python 3.3+? 🤔

Indeed, there has been a significant change! In Python 3.3+, the __init__.py file is no longer a strict requirement for packages to be imported. Instead, you can directly reference the modules within the package without it. 😮🎉

In Python 2.7, without the __init__.py files in both ~/Playground/a and ~/Playground/a/b, the imports fail:

~ $ PYTHONPATH=Playground python
>>> import a
ImportError: No module named a
>>> import a.b
ImportError: No module named a.b
>>> import a.b.module
ImportError: No module named a.b.module

However, in Python 3.3+ onwards, as you have observed, the empty __init__.py files are no longer necessary. Now, you can freely import without any issues! 😃🎉

So, why were the __init__.py files previously required in Python 2.7? Well, they served as indicators that a directory was indeed a package. In Python 3.3+, this requirement was lifted to improve the simplicity and usability of importing modules.

⚠️ However, keep in mind that if you have any special initialization or code you want to execute when a package is imported, you can still use the __init__.py file. It's completely optional, but it gives you a way to perform custom setup tasks when needed. 🧰💪

To sum it up, in Python 3.3+ packages, the __init__.py file is no longer required for import. You can directly reference modules within a package without any issues. How awesome is that? 😎🚀

I hope this blog post shed some light on this topic for you. If you have any further questions or insights, feel free to share them in the comments below. Let's keep the conversation going! 🗣️💬

Until next time, happy coding! ✌️❤️