#统计某句英文句子中有多少某个字母字母
def count_letter(s,letter):
result=0
for i in s:
if i==letter:
result+=1
return result
s="snwoosdjodmo"
print("总共有%i个o" %count_letter(s,'o'))
print("总共有%i个s" %count_letter(s,'s'))
