Sometimes we'll need to update data inside a string without creating a whole new string.
We can replace a part of a string stored inside a variable by firt coding the variables's name and the instruction replace().
In side the parentheses, we add the part we want to replace, like "afternoon", a comma, and then the new value, "morning".
>>> a = "Good morning"
>>> a.replace("morning","afternoon")
'Good afternoon'