s = 'CCACCCTCGTGGTATGGCTAGGCATTCAGGAACCGGAGAACGCTTCAGACCAGCCCGGACTGGGAACCTGCGGGCAGTAGGTGGAAT'
print len(s)
count = 0
for char in range(len(s)):
print char
'''if list(s()) == 'C':
count += 1
else s(char) == 'G': # s(g)是函数的调用方式,但是s是个字符串,不是函数
count = count + 1'''
if char == 'C' or char == 'G'
count += 1 #假如你要统计‘c’和‘g’的个数,可以这样
print count
你是不是要统计 C 和 G 出现的次数?
s = 'CCACCCTCGTGGTATGGCTAGGCATTCAGGAACCGGAGAACGCTTCAGACCAGCCCGGACTGGGAACCTGCGGGCAGTAGGTGGAAT'
print len(s)
count_C = 0
count_G = 0
for char in s:
#print char
if char == 'C':
count_C += 1
if char == 'G':
count_G = count_G + 1
print 'C count: '+str(count_C),'G count: '+str(count_G)