.. meta::
    :description lang=en:
        xlSlim makes it easy to use Python to fetch Yahoo Finance prices and return these to Excel.

Loading Stock Prices from Yahoo! Finance
========================================

.. _yfinance: https://pypi.org/project/yfinance/
.. _Yahoo! Finance: https://finance.yahoo.com/

The Python `yfinance`_ package can be used to download prices from `Yahoo! Finance`_ (please read the legal disclaimers referenced at `yfinance`_)

xlSlim makes it easy to use the yfinance package to download prices into Excel.

.. warning::
	The pandas functionality shown requires a premium licence. See :doc:`/reference/licensing`


We will use this Python code to download the prices.

.. code-block:: python

	# example of using yfinance package to source prices and other data for financial instruments
	# pip install yfinance to get the package
	import yfinance as yf
	import pandas as pd


	def get_historical_prices(ticker_name: str, period: str) -> pd.DataFrame:

		assert (
			len(ticker_name.split(" ")) == 1
		), "get_historica_prices works with one ticker only"

		tick = yf.Ticker(ticker_name)

		return tick.history(period)




.. note::
	All the Python code and Excel files shown are available from github in the `xlslim-code-samples`_ repo.

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


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\yfinance.py","C:\Users\russe\anaconda3\envs\py37")
	
.. note::
	yfinance is not available in the Python installation bundled with xlSlim. The Python module must be registered with an existing Python installation that has yfinance installed. See `yfinance`_ for installation details.

You should see a message similar to this confirming the module registration:

.. image:: ../_static/yfinance_registration.png
  :width: 400
  :alt: Register yfinance function

The `get_historical_prices()` function is now available in Excel. Let's load the last 30 days of MSFT prices: ::

    =get_historical_prices("MSFT", "30d")

A cache object handle is returned to Excel. Internally xlSlim has put the pandas DataFrame into an in-memory cache.

.. image:: ../_static/yfinance_result.png
  :width: 400
  :alt: Yahoo Finance data in Excel

The :func:`ViewPyObject` can be used to view the data in Excel: ::

    =ViewPyObject(A2)

.. image:: ../_static/yfinance_view_result.png
  :width: 400
  :alt: View Yahoo Finance data in Excel

This example shows how neatly xlSlim handles pandas DataFrames.