Python insert a line break in a string after character "X"

Question

What is the python syntax to insert a line break after every occurrence of character "X" ? This below gave me a list object which has no split attribute error

for myItem in myList.split('X'):
  myString = myString.join(myItem.replace('X','X\n'))

Answer 1

myString = '1X2X3X'
print (myString.replace ('X', 'X\n'))

Answer 2

You can simply replace X by "X\n"

myString.replace("X","X\n")