input: 
  def delete_key(dic: dict, k: str) -> None:
      """ Delete a specified key from a given dictionary.
      >>> d = {'foo': 1, 'bar': 2, 'baz': 3}
      >>> delete_key(d, 'baz')
      >>> d
      {'foo': 1, 'bar': 2}
      """
      if k in dic:
          del dic[k]
  
output:     if k in dic:
          del dic[k]