Introduction to Computer Science and Programming in Python

Lecture 2

1. Strings

   What is the value of variable `u` from the code below?

   once = "umbr"
   repeat = "ella"
   u = once + (repeat+" ")*4
   

   umbrella ella ella ella check

   umbrellaellaellaella close

   umbrella close

   umbrella4 close

   Check

2. Comparisons

   What does the code below print?

   pset_time = 15
   sleep_time = 8
   print(sleep_time > pset_time)
   derive = True
   drink = False
   both = drink and derive
   print(both)
   

   False then False check

   False then True close

   True then False close

   True then True close

   Check   Show Solution

3. Branching

   What’s printed when x = 0 and y = 5?

   x = float(input("Enter a number for x: "))
   y = float(input("Enter a number for y: "))
   if x == y:
    if y != 0:
    print("x / y is", x/y)
   elif x < y:
    print("x is smaller")
   else:
    print("y is smaller") 
   

   x is smaller check

   y is smaller close

   x / y is 0.0 close

   Check   Show Solution

4. While Loops

   In the code below from Lecture 2, what is printed when you type “Right”?

   n = input("You're in the Lost Forest. Go left or right? ")
   while n == "right":
    n = input("You're in the Lost Forest. Go left or right? ")
   print("You got out of the Lost Forest!")
   

   You’re in the Lost Forest. Go left or right? close

   You got out of the Lost Forest! check

   Check   Show Solution

5. For Loops

   What is printed when the below code is run?

   mysum = 0
   for i in range(5, 11, 2):
    mysum += i
    if mysum == 5:
     break
     mysum += 1
   print(mysum)
   

   5 check

   6 close

   21 close

   24 close

   Check   Show Solution