.. meta::
    :description lang=en:
		Getting started with xlSlim is very easy and in less than a minute you will be calling your first Python function from Excel.

Quickstart
==========

Let's start with this simple Python module that contains these functions to calculate the area of various shapes. As you can see, the code is very simple and there are *no changes* to support xlSlim.

.. code-block:: python

	# Various functions to calculate areas
	import math


	def area_circle(r):
		return math.pi * r ** 2


	def area_square(l):
		return l * l


	def area_rectangle(l, w):
		return l * w

.. note::
	All the Python code and Excel files shown are available from github in the `xlslim-code-samples`_ repo. I highly recommend downloading the samples from github. The Excel workbooks contain many tips and tricks.


.. _xlslim-code-samples: https://github.com/RusselWebber/xlslim-code-samples/archive/refs/heads/main.zip

..
	TODO - Installation doc link

Save the Python code as a new file on your PC. I saved the file in my Documents folder.

Open Excel and enter this :func:`RegisterPyModule` formula (amending the location to match where you saved the file): ::

	=RegisterPyModule("C:\Users\russe\Documents\quickstart.py")
	
That's it! The functions are now available to use in Excel.

.. image:: ../_static/quickstart_basic_area_circle.png
  :width: 400
  :alt: Quick start showing area_circle function in Excel
  
Type Hints and Doc strings
--------------------------

To make full use of xlSlim's capabilities, use type hints and doc strings to provide more information about your functions.

Replace the quickstart.py code with this:

.. code-block:: python

	# Various functions to calculate areas
	# With doc strings and type hints
	import math


	def area_circle(r: float) -> float:
		"""Calculates the area of a circle as pi x r x r"""
		return math.pi * r ** 2


	def area_square(l: float) -> float:
		"""Calculates the area of a square as l x l"""
		return l * l


	def area_rectangle(l: float, w: float) -> float:
		"""Calculates the area of a rectangle as l x w"""
		return l * w

And re-register the module in Excel::

	=RegisterPyModule("C:\Users\russe\Documents\quickstart.py")
	
Now the function looks much better, with documentation and the correct types.

.. image:: ../_static/quickstart_basic_area_circle_annotated.png
  :width: 400
  :alt: Quick start showing area_circle function in Excel with docs and hints