编写一个函数实现计算大小写字母的个数q5、计算Hello World这一字符串中大写字母个数有多少？将结果保存到a5中；q6、计算Hello World这一字符串中小写字母的个数有多少？将结果保存到a6中；python

def count_letters(string): uppercase_count = 0 lowercase_count = 0 for char in string: if char.isupper(): uppercase_count += 1 elif char.islower(): lowercase_count += 1 return uppercase_count, lowercase_count

a5, a6 = count_letters('Hello World') print("大写字母个数:", a5) print("小写字母个数:", a6)