Directories and packages

Both directories and packages are ways to organize and structure your code. However, they serve slightly different purposes

Directories:

In Python, directories are simply folders on your file system that contain Python files (modules) or other directories.
They are used primarily for organizing and storing your Python source code files.
Directories themselves are not directly importable in Python. Instead, Python files within directories are imported as modules.

Packages:

Packages, on the other hand, are special directories that contain an additional __init__.py file. This file can be empty or can contain Python code.
The presence of the __init__.py file indicates to Python that the directory should be treated as a package.
Packages allow you to organize related modules (Python files) into a single namespace.
Packages can also contain sub-packages, which are simply packages within packages, forming a hierarchical structure.
When you import a package in Python, you are actually importing the __init__.py file of that package.

Suppose we have the following directory structure:

my_project/
├── main.py
└── my_packages/
    ├── __init__.py
    ├── package1/
    │   ├── __init__.py
    │   ├── module1.py
    │   └── module2.py
    └── package2/
        ├── __init__.py
        ├── module3.py
        └── subpackage/
            ├── __init__.py
            └── module4.py

my_project/ is the main directory of our project.
main.py is the entry point for our application.
my_packages/ is the parent package directory.
package1/ and package2/ are two packages within my_packages/, each with their own __init__.py files indicating they are packages.
subpackage/ is a sub-package of package2/.
Each package and sub-package can contain one or more modules, indicated by .py files.

Here's a brief example of what the files might contain:

main.py:

from my_packages.package1 import module1
from my_packages.package2 import module3
from my_packages.package2.subpackage import module4

module1.foo()
module3.bar()
module4.baz()