csv file question

Dear list
I have a csv file having the following contents.
col1 col2 col3
"A", "1","2"
"B","1",   "3"
"C","2","4"
"D","1","5"
"A","1","6"
"B","2","7"
"C","2","8"
" ","3","9"

Now I want to implement a logic which will show me the summarize records as
follows
col1 count
A-   2
B -  2
C -  2
D -  1

and one more question how the null value will be handled

Thanks & Regards
Anirban Adhikary.