Set and Booleans

There are two other object types in Python that we should quickly 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



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x = set()



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# We add to sets with the add() method
x.add(1)



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#Show
x









    Out[4]:





{1}

Note the curly brackets. This does not indicate a dictionary! Although you can draw analogies as a set being 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?



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# Add a different element
x.add(2)



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#Show
x









    Out[6]:





{1, 2}



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# Try to add the same element
x.add(1)



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#Show
x









    Out[9]:





{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:



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# Create a list with repeats
l = [1,1,2,2,3,4,5,6,1,1]



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# Cast as set to get unique values
set(l)









    Out[12]:





{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 (we will dive deeper into them later in this course).



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# Set object to be a boolean
a = True



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#Show
a









    Out[16]:





True

We can also use comparison operators to create booleans. We will go over all the comparison operators later on in the course.



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# Output is boolean
1 > 2









    Out[17]:





False

We can use None as a placeholder for an object that we don't want to reassign yet:



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# None placeholder
b = None

Thats it! You should now have a basic understanding of Python objects and data structure types. Next, go ahead and do the assessment test!



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