I have a dataset that looks something like this:

    Column A  Column B  Column C  
1       D        40       hex       
2       E        50       def       
3       E        70       foo       
4       D        60       bar       
5       E        90       key 

and I want to sort the dataframe by the values in column A, keeping the other values in the associated rows together to get something like this:

    Column A  Column B  Column C  
1       D        40       hex       
4       D        60       bar      
3       E        70       foo       
2       E        50       def        
5       E        90       key 

or at least select a smaller dataframe with just D or E value rows like this:

    Column A  Column B  Column C  
3       E        70       foo       
2       E        50       def        
5       E        90       key 

I was looking into using the df.loc function, but I do not know what index values the “D” rows are at (and they are less that ~5% of over 13,000 rows). Is there a multi-indexing way doing this? Or should I be using a different function entirely?