This document discusses operations on sets and dictionaries in Python. It covers the main set operations - union, intersection, difference, and symmetric difference. It provides examples of using operators and methods to perform these operations on sets. It also discusses dictionary methods for accessing elements, updating values, and converting lists to dictionaries using zip(). Exercises are included to practice set operations and dictionary methods.

1. Operation: Sets and Dictionary
Lesson 2.3
CHAPTER
2

2. What are the string functions?

3. How do you get input
from the user?

4. Set Operations
In This Lesson
Operations in Dictionary

5. Set Operations

6. Set Operations
• Union
• Intersection
• Difference
• Symmetric difference

7. Union
• Union sets is a set of all elements from both sets.
• It is performed using the “|” operator and the
union() method.

8. Example
x = {1,2,3,4,5}
y = {3,4,5,6,7}
print(x|y)
print(x.union(y))
{1, 2, 3, 4, 5, 6, 7}
{1, 2, 3, 4, 5, 6, 7}

9. Answer This
What is a union set?

10. Intersection
• Intersection is sets is a set of elements that are
common to both sets.
• It uses the “&” operator and the intersection() method.

11. Example
x = {1,2,3,4,5}
y = {3,4,5,6,7}
print(x&y)
print(x.intersection(y))
{3, 4, 5}
{3, 4, 5}

12. Difference
• Difference in sets is a set where the difference of set x
to y (x - y) is a set of elements that are only in x but not
in y.
• It is performed using the “-” operator and the
difference() method.

13. Example
x = {1,2,3,4,5}
y = {3,4,5,6,7}
print(x-y)
print(x.difference(y))
print(y-x)
print(y.difference(x))
{1, 2}
{1, 2}
{6, 7}
{6, 7}

14. Symmetric Difference
• Symmetric difference in sets is a set where the
symmetric difference of x and y is a set of elements
that is not found in both sets.
• It is performed using the “^” operator and the
symmetric_difference() method.

15. Example
x = {1,2,3,4,5}
y = {3,4,5,6,7}
print(x^y)
print(x.symmetric_difference(y))
print(y^x)
print(y.symmetric_difference(x))
{1, 2, 6, 7}
{1, 2, 6, 7}
{1, 2, 6, 7}
{1, 2, 6, 7}

16. Answer This
How do you describe the symmetric
difference in sets?

17. Find the Union, Intersection, Difference and Symmetric
Difference of the following sets:
A = {2,4,12,42,9,17}
B = {3,12,17,5,34,7,10}
C = {34,25,7,42,4,6,11,55}
Exercise

18. Operations in Dictionary

19. Dictionary Methods
• Get()
• Clear()
• Copy()
• Items()
• Update()
• Pop()
• Zip()

20. Example
students = {"Name":"David","Age":16}
print(students.get("Name"))
students["Age"]=30
print(students.get("Age"))
print(students.pop("Name"))
David
30
David

21. Answer This
How do you differentiate set operations
from dictionary operations?

22. Other Dictionary Methods
• fromkeys(seq[, v])
• items()
• keys()
• popitem()
• setdefault(key[,d])
• values()

23. Answer This
What are the methods in accessing
the elements of the dictionary?

24. Create a program to convert the following lists to a
dictionary. Hint: use zip().
employee = ["Cynthia","Austin","Cesar"]
salary = [40000,30000,45000]
Output:
{'Cynthia': 40000, 'Austin': 30000, 'Cesar': 45000}
Exercise

25. Answer This
What are the characteristics of each
type of set operation?

26. Do the activity on
page 84.
Lesson Exercises