All of the collections we've looked at previously have been sequences: str
, bytes
, tuple
, and list
have items which can be accessed by their position within the collection. A set
collection is an unordered collection where items are present or absent.
Items in a set
collection must be immutable; they must provide a proper hash value as well as an equality test. This means that we can create sets of numbers, strings, and tuples. We can't easily create a set of lists or a set of sets.
The syntax of a set
display is a sequence of expressions wrapped in {}
.
Here's an example set
built using numbers:
>>> fib_set = {1, 1, 3, 5, 8} >>> fib_set {8, 1, 3, 5}
We've created a set
object by enclosing the values in {}
. This syntax looks very similar to the syntax for creating list
or tuple
. Note that the elements in the set
collection are displayed in a different order. There's no guarantee what the order will be; different implementations may show different orders...