Update uv.md

Author: jAniceto

programming-notes/python/uv.md

@@ -47,6 +47,70 @@ When starting a new project you can specify the Python version using:
 $ uv init project_name --python 3.11
 ```
 
+### Types of projects
+
+**Application** projects are suitable for web servers, scripts, and command-line interfaces.
+
+```
+uv init example-app
+uv init example-app --app
+```
+
+```
+example-app/
+├─ main.py
+├─ pyproject.toml  # [project] metadata only, no [build-system]
+├─ README.md
+└─ .python-version
+```
+
+The `pyproject.toml` includes basic metadata. It does not include a build system, it is not a package and will not be installed into the environment
+
+**Packaged application** projects are suitable if you require a package, for instance, a command-line interface that will be published to PyPI or if you want to define tests in a dedicated directory.
+
+```
+uv init --package example-pkg
+```
+
+```
+example-pkg/
+├─ src/
+│  └─ example_pkg/
+│     ├─ __init__.py
+│     ├─ cli.py   # CLI entrypoint code
+│     └─ core.py
+├─ tests/
+│  └─ test.py
+├─ pyproject.toml  # [project] + [project.scripts] + [build-system]
+├─ README.md
+└─ .python-version
+```
+
+The source code is moved into a src directory with a module directory and an `__init__.py` file. A build system is defined, so the project will be installed into the environment.
+
+
+**Library** projects provide functions and objects for other projects to consume. Libraries are intended to be built and distributed, e.g., by uploading them to PyPI. Using `--lib` implies `--package`. Libraries always require a packaged project.
+
+```
+uv init --lib example-lib
+```
+
+```
+example-lib/
+├─ src/
+│  └─ example_lib/
+│     ├─ __init__.py  # library package root
+│     └─ module.py # your library code
+├─ tests/
+│  └─ test.py
+├─ pyproject.toml  # [project] + [build-system]
+├─ README.md
+└─ .python-version
+```
+
+As with a packaged application, a `src` layout is used. A `py.typed` marker is included to indicate to consumers that types can be read from the library. A `src` layout ensures that the library is isolated from any python invocations in the project root and that distributed library code is well separated from the rest of the project source. A build system is defined, so the project will be installed into the environment.
+
+
 ## Installing packages
 
 To add packages: