Python Set and Booleans
Updated: Sep 1, 2020

Python Set and Booleans
There are two other object types in Python that we should cover: Sets and Booleans.
Sets
Sets are an unordered collection of unique elements. We can construct them by using the set() function. Let's go ahead and make a set to see how it works.
Example:
x = set()
# We add to sets with the add() method
x.add(1)
#Show
x
Output:
1
Note the curly brackets. This does not indicate a dictionary! Although you can draw analogies as a set is a dictionary with only keys.
We know that a set has only unique entries. So what happens when we try to add something that is already in a set?
Example:
# Add a different element
x.add(2)
#Show
x
Output:
{1, 2}
Example:
# Try to add the same element
x.add(1)
#Show
x
Output:
{1, 2}
Notice how it won't place another 1 there. That's because a set is only concerned with unique elements! We can cast a list with multiple repeat elements to a set to get the unique elements. For example:
Example:
# Create a list with repeats
list1 = [1,1,2,2,3,4,5,6,1,1]
# Cast as set to get unique values
set(list1)
Output:
{1, 2, 3, 4, 5, 6}
Booleans
Python comes with Booleans (with predefined True and False displays that are basically just the integers 1 and 0). It also has a placeholder object called None. Let's walk through a few quick examples of Booleans.
They are of type bool -
Example:
# Set object to be a boolean
a=True
# Show
a
Output:
True
We can also use comparison operators to create booleans.
Example:
# Output is boolean
1 > 2
Output:
False
We can use None as a placeholder for an object that we don't want to reassign yet:
Example:
# None placeholder
b = None
# Show
print(b)
Output:
None
That's it! You should now have a basic understanding of Python objects and data structure types.