input: 
  def count_switches(s: str) -> int:
      """
      Provided with a string s, which is 0-indexed and typed by a user. A switch occurs when the user uses a different key from the previously used one. For example, s = "ab" involves a switch, whereas s = "bBBb" does not.
  
      Calculate the number of times the user switched keys.
  
      Note: Changes involving shift or caps lock are not counted as switches. For instance, typing 'a' followed by 'A' is not regarded as a switch.
  
      Examples:
      >>> s = "aAbBcC"
      2
      >>> s = "AaAaAaaA"
      0
  
      Constraints:
      1 <= s.length <= 100
      s is made up of both uppercase and lowercase English letters.
      """
  
output:     s = s.lower()
      switches = 0
      for i in range(1, len(s)):
          if s[i] != s[i-1]:
              switches += 1
      return switches