Fill in the gaps in the initials function so that it returns the initials of the words contained in the phrase received, in upper case.

def get_initials(fullname):
  xs = (fullname)
  name_list = xs.split()

  initials = ""

  for name in name_list:  # go through each name
    initials += name[0].upper()  # append the initial

  return initials