1. Logical Operators, Boolean Data Types
Let’s get coding!

2. Logical Operators
Python has a set of logical operators that allow you to combine Boolean expressions in a single IF selection statement
These are the three we will be using:
and or
not

3. Logical Operators: “and”
“and” can be used to combine two different Boolean expressions
These selection statements will only hold true if both conditions are met
True and True  True
True and False  False
False and True  False
False and False  False

4. Logical Operators: “and”
a = 5 b = 10 print (a > b and a > 1) print (a > 1 and b > a) print (a == 5 and b < 100) print (a > 1 and b < 1 and b > a) print (a > 1 and b > 1 and b > a)

5. Logical Operators: “and”
a = 5 b = 10 print (a > b and a > 1) False print (a > 1 and b > a) print (a == 5 and b < 100) print (a > 1 and b < 1 and b > a) print (a > 1 and b > 1 and b > a)

6. Logical Operators: “and”
a = 5 b = 10 print (a > b and a > 1) False print (a > 1 and b > a) True print (a == 5 and b < 100) print (a > 1 and b < 1 and b > a) print (a > 1 and b > 1 and b > a)

7. Logical Operators: “and”
a = 5 b = 10 print (a > b and a > 1) False print (a > 1 and b > a) True print (a == 5 and b < 100) True print (a > 1 and b < 1 and b > a) print (a > 1 and b > 1 and b > a)

8. Logical Operators: “and”
a = 5 b = 10 print (a > b and a > 1) False print (a > 1 and b > a) True print (a == 5 and b < 100) True print (a > 1 and b < 1 and b > a) False print (a > 1 and b > 1 and b > a)

9. Logical Operators: “and”
a = 5 b = 10 print (a > b and a > 1) False print (a > 1 and b > a) True print (a == 5 and b < 100) True print (a > 1 and b < 1 and b > a) False print (a > 1 and b > 1 and b > a) True

10. Logical Operators: “and”
You can use the “and” operator to combine as many Boolean expressions as you would like
In any event, they would all need to hold True in order for the selection statement to be True

11. Logical Operators: “or”
“or” can also combine two expressions
But this time, the selection statement will hold true if at least one of the conditions are met
True or True  True
True or False  True
False or True  True
False or False  False

12. Logical Operators: “or”
a = 5 b = 10 print (a > b or a > 1) print (a > 1 or b > a) print (a == 5 or b < 100) print (a > 1 or b < 1 or b > a) print (a > 1 or b > 1 or b > a)

13. Logical Operators: “or”
a = 5 b = 10 print (a > b or a > 1) True print (a > 1 or b > a) print (a == 5 or b < 100) print (a > 1 or b < 1 or b > a) print (a > 1 or b > 1 or b > a)

14. Logical Operators: “or”
a = 5 b = 10 print (a > b or a > 1) True print (a > 1 or b > a) True print (a == 5 or b < 100) print (a > 1 or b < 1 or b > a) print (a > 1 or b > 1 or b > a)

15. Logical Operators: “or”
a = 5 b = 10 print (a > b or a > 1) True print (a > 1 or b > a) True print (a == 5 or b < 100) True print (a > 1 or b < 1 or b > a) print (a > 1 or b > 1 or b > a)

16. Logical Operators: “or”
a = 5 b = 10 print (a > b or a > 1) True print (a > 1 or b > a) True print (a == 5 or b < 100) True print (a > 1 or b < 1 or b > a) True print (a > 1 or b > 1 or b > a)

17. Logical Operators: “or”
a = 5 b = 10 print (a > b or a > 1) True print (a > 1 or b > a) True print (a == 5 or b < 100) True print (a > 1 or b < 1 or b > a) True print (a > 1 or b > 1 or b > a) True

18. Logical Operators: “not”
“not” operates by reversing the statement
In other words, for statements that hold True, it will yield False and vice versa

19. Logical Operators: “not”
a = 5 b = 10 print (not a > b) print (not a > 1) print (not a == 5) print (not b < 1) print (not b > a)

20. Logical Operators: “not”
a = 5 b = 10 print (not a > b) True print (not a > 1) print (not a == 5) print (not b < 1) print (not b > a)

21. Logical Operators: “not”
a = 5 b = 10 print (not a > b) True print (not a > 1) False print (not a == 5) print (not b < 1) print (not b > a)

22. Logical Operators: “not”
a = 5 b = 10 print (not a > b) True print (not a > 1) False print (not a == 5) False print (not b < 1) print (not b > a)

23. Logical Operators: “not”
a = 5 b = 10 print (not a > b) True print (not a > 1) False print (not a == 5) False print (not b < 1) True print (not b > a)

24. Logical Operators: “not”
a = 5 b = 10 print (not a > b) True print (not a > 1) False print (not a == 5) False print (not b < 1) True print (not b > a) False

25. Logical Operators: “not”
password = “secret” user_password = input(“Password: “) if not user_password == password: print (“Invalid! Wrong password”) else: print(“Welcome!”)

26. Warning About Logical Operators
choice = input(“Try again?“) if choice == “Yes” or “yes”: # this causes a problem because “yes” loop( ) # is not a Boolean expression else: print(“Okay goodbye”)

27. Warning About Logical Operators
I’ve seen many of you guys try using these operators but incorrectly
In this situation, when we want Python to consider a conjunction of two conditions, we need to make sure that Python reads them both as conditions exclusively
The word “yes” in this case and really any single string is not a condition in itself, it will actually just hold True all the time
So let’s take a look at the correct way to use these operators …

28. Warning About Logical Operators
choice = input(“Try again?“) if choice == “Yes” or choice == “yes”: loop( ) else: print(“Okay goodbye”)

29. Augmented Assignment Operator
I’ve been holding out on you slightly …
Python has a shortcut for the augmentations we’ve been implementing in our codes
When we want to add, subtract, multiply, divide, etc continuously on a variable, we can use the augmented assignment operators

30. Augmented Assignment Operator
Example
Equal to +=
C += 5
C = C + 5 –=
C –= 4
C = C – 4 *=
C *= 3
C = C * 3 /=
C /= 2
C = C / 2 %=
C %= 6
C = C % 6

31. Warning About Logical Operators
def function(): x = 10 if x == 0: print(x) else: x –= 1 function()

32. Boolean Data Types
As we discussed, there are such data types we call Boolean data types, or “bool”s for short
These are data types like integers, floats and strings
It only consists of two options: True/False
However, these Boolean data types can be held in variables

33. Boolean Data Types
As we discussed, there are such data types we call Boolean data types, or “bool”s for short
These are data types like integers, floats and strings
It only consists of two options: True/False
However, these Boolean data types can be held in variables

34. Boolean Data Types
variable = True if variable: print (“It works!”)

35. Boolean Data Types
This method of assigning variables as bool’s can be helpful when programs become complex and have various different “states”
We may use variables to hold Boolean values and we can flip their values once a certain condition is met

36. Boolean Data Types loop = True choice = input(“Again?”)
def function():
loop = True
choice = input(“Again?”)
if choice == “no”:
loop = False
elif loop:
function()

37. Mini Hackathon

38. Intermission: The Akinator

39. The Akinator: How it works

40. The Akinator: How it works
Females

41. The Akinator: How it works
Female Adults

42. The Akinator: How it works
Female Adults with Red Hair

43. Mini Hackathon
Good luck!