Merge branch 'master' into python-string-interpolation

Author: lpozo

pivot_tables/README.md

@@ -0,0 +1,5 @@
+These are the three download files you can use with the Real Python tutorial [How to Create a Pivot Table With pandas](https://realpython.com/how-to-pandas-pivot-table/):
+
+code_downloads.ipynb contains the main code from the tutorial.
+solutions.ipynb contains sample solutions to the various exercises.
+sales_data.csv contains the source data used throughout the tutorial.