input: Write a function to detect the vowel in a given string. If a vowel is found, return the vowel. If no vowel is found, return an empty string.
  def vowelCheck(inputString): 
      vowels = ['a','e','i','o','u','A','E','I','O','U'] 
      for x in inputString: 
          if x in vowels: 
              return x
  return ""
  
  assert vowelCheck("Hello World") == "e"
  assert vowelCheck("Python") == "o"
  assert vowelCheck("Rhythm") == ""
  assert vowelCheck("AEIOU") == "A"
  assert vowelCheck("") == ""
output: def vowelCheck(inputString): 
      vowels = ['a','e','i','o','u','A','E','I','O','U'] 
      for x in inputString: 
          if x in vowels: 
              return x
      return ""