Lists are mutable sequences. There are immutable sequences as well. These are called tuples. Here we create a tuple with A3 and -0.2 in it, and we assign it to variable tup. Tuples and lists use the same index notation. Here, we look at tuple at index zero, index one, index two, and also, we can use negative indices such as tup at index -one. Slicing a tuple, produces a tuple. Here, we slice tup up two, but not including index two and we can also slice tup from index one up to, but not including index three. We cannot change the tuples, tuples are inmutable. A sign-in into a tuple produces a type error, tuple object does not support item assignment. Lists have methods append, count, extend, index, insert, pop, remove, reverse, and sort. But tuples only have count and index. The other methods in list all modify the list. Like lists, we can iterate over the items in a tuple. Function len, works on tuples. We can iterate over the indices of a tuple. To create a tuple, put a comma separated list of values in between parentheses. What about, one element tuples? If we just put, a value in between parentheses that you says, parenthesize this mathematical expression, and it get's us back the value. To create a one element tuple, put a comma after the value inside the parentheses. Empty tuples do not require this comma.