[Tutor] counting elements in list

[kumar s]

Hi group:

I have a list:

 k = ['T', 'C', 'T', 'T', 'T', 'T', 'T', 'T', 'T', 'C', 'T', 'T', 'T', 'C', 'T', 
'T', 'T', 'C', 'C', 'T', 'T', 'T', 'C', 'T', 'T', 'T', 'T', 'T', 'T']

the allowed elements are A or T or G or C. List can have any number of A or T or 
G or C

My aim is to get a string ouput with counts of each type A or T or G or C.  

A:0\tT:23\tG:0\tC:6  

from the above example, I could count T and C and since there are no A and G, I 
want to print 0 for them. I just dont know how this can be done. 




>>> d = {}
>>> for i in set(k):
...     d[i] = k.count(i)
...
>>> d
{'C': 6, 'T': 23}


>>> for keys,values in d.items():
...     print keys+'\t'+str(d[keys])
...
C       6
T       23

the other way i tried is:
>>> k.count('A'),k.count('T'),k.count('G'),k.count('C')
(0, 23, 0, 6)


 how can I get counts for those elements not represented in list and print 
them.  appreciate your help. 


thanks
kumar