Trying to create a new dataframe based on data of another dataframe's columns

Question

I'm trying to create a new dataframe based on existing dataframe's data, I have the following data frame:

And I need to create a new dataframe which sums the amount of workers joined each department every year.

I've tried the following:

emp_dept_sal_s[['dept_name','Year']].groupby(['dept_name','Year']).count()

but the output is:

So basically, the question is how do I relative to both columns (dept_name and Year)? Thanks!

Answer 1

emp_dept_sal_s.groupby(by=['dept_name','Year']).count()