A=0
G=0
T=0
C=0
with open('/Users/rebka/PycharmProjects/Project2/mutant_dna.txt') as dna_file:

    for symbol in dna_file.read():
           print(symbol)
           if symbol == 'A':
            A+=1
           elif symbol == 'G':
            G+=1
           elif symbol == 'T':
            T+=1
           elif symbol == 'C':
            C+=1
print (f"There are {A} A's in this number.")
print (f"There are {G} G's in this number.")
print (f"there are {T} T's in this number.")
print (f"there are {C} C's in this number.")