Write a function that takes a string s and returns the count of vowels (a, e, i, o, u) in it. The function should handle both uppercase and lowercase vowels.
Example 1:
Input: s = "Hello World"
Output: 3
Explanation: The vowels are 'e', 'o', and 'o'.
Example 2:
Input: s = "Python Programming"
Output: 4
Explanation: The vowels are 'o', 'o', 'a', and 'i'.
s can be empty.s will not exceed 1000 characters.s = "Hello World"Output3WhyThe vowels are 'e', 'o', and 'o'.s = "Python Programming"Output4WhyThe vowels are 'o', 'o', 'a', and 'i'.The input string `s` can be empty.The length of `s` will not exceed 1000 characters.def count_vowels(s):
