IF AND statement only outputs ELSE statement Python

I have a function that generates different dataframes, the 3rd dataframe causes an error because it contains a final row of NaN values at the bottom.

I tried an if-else conditional statement to remove the row of NaN values, but everytime I do, it keeps outputting the NaN values.

       ma =1
       year = 3
       df

       if ma >0 and year == 3:

                     df[0:-1]

       else:

                     df

I also tried a nested if statement, but that produced the same output of NaN values.

      ma_path = "SMA"
      year_path = "YEAR_3"

      if ma_path == ["SMA"]:
           if year_path == ["YEAR_3"]:


                             df[0:-1]

      else:
                             df

I'm sure it's something simple that I've missed. Can anyone help? Thanks in advance.