I am using pandas as a db substitute as I have multiple databases (oracle, mssql, etc) and I am unable to make a sequence of commands to a SQL equivalent.
I have a table loaded in a DataFrame with some columns:
YEARMONTH, CLIENTCODE, SIZE, .... etc etc
In SQL, to count the amount of different clients per year would be:
SELECT count(distinct CLIENTCODE) FROM table GROUP BY YEARMONTH;
And the result would be
How can I do that in pandas?