LPTHW Exercises 27 - 31
(12/2/13 -- 6:30pm PST)
Control Flows
Review
- Known Python data types?
- What are functions? How do we define and call them?
- What is scope? Local? Global?
Boolean Data Type
One of two values (True or False)
Think of it like a light switch
It represents either on or off
Exercise 27: Truth Expressions
bool() --> convert a data type into a Bolean value
True --> Boolean data type. On switch (declares something is truth)
False --> Boolean data type. Off switch (declares something is false)
and --> Operator. Produces True if ALL operands are true, else False
or --> Operator. Produces True if ANY operands are true, else False
not --> Operator. Produces inverse Boolean (not True == False)
== --> Operator. Does equal (5 ==3)
!= --> Operator. Does not equal (5 !=3)
>= --> Operator. Greater than OR equal to (4 >=3)
<= --> Operator. Less than OR equal to (2 <=3)
Problem Set: Truth Tables
See "problem_set_two.py" in the IDE
Exercise 28: Boolean Logic Expressions
not (1 == 1 and 0 != 1)
not (10 == 1 or 1000 == 1000)
not ("testing" == "testing" and "Zed" == "Cool Guy")
1 == 1 and not ("testing" == 1 or 1 == 0)
"chunky" == "bacon" and not (3 == 4 or 3 == 3)
3 == 3 and not ("testing" == "testing" or "Python" == "Fun")
IF statements
How do we create different branches or flows?
people = 20 cats = 30 dogs = 15 if people < cats: print "Too many cats! The world is doomed!" if people > cats: print "Not many cats! The world is saved!" if people < dogs: print "The world is drooled on!" if people > dogs: print "The world is dry!" dogs += 5 if people >= dogs: print "People are greater than or equal to dogs." if people <= dogs: print "People are less than or equal to dogs." if people == dogs: print "People are dogs."
Else/Elif Statements
How about many branches?
people = 30 cars = 40 buses = 15 if cars > people: print "We should take the cars." elif cars < people: print "We should not take the cars." else: print "We can't decide." if buses > cars: print "That's too many buses." elif buses < cars: print "Maybe we could take the buses." else: print "We still can't decide." if people > buses: print "Alright, let's just take the buses." else: print "Fine, let's stay home then."
Control Flow: conditional statements and loops
By benjaminplesser
Control Flow: conditional statements and loops
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