This is my first time posting :)
In a Python data frame, how could I get the total for just certain columns? For example in the data frame below, the total for column "c_2" and column "c_3"
           X           c_1       c_2             c_3   
0          A           84        10.0           70.0   
1          B           76         70.0          125.0   
2          C           25         79.0           16.0   
3          D           28         28.0           31.0   
4          E           15         20.0           15.0   
5          F           80        195.0           10.0  
I've used df['c_2'].sum() to get the total for one column at a time, but is there a way to get the total of several, specific columns at a time? In this example the total for c_2 and total for c_3 separately. 
I've seen examples for getting the total for all columns, but not examples for just certain columns.
Thank you!
