Midterm Review: Python Problem Sets 3

1. Is there a difference between these two lines of code? Would they result in an runtime error?

   x = (a = 5)
   

   x = a = 5
   

    

2. What is the value of a after the second assignment?

   >>> print(a := 10)
   >>> a = 20
   >>> print(a := a + 5)
   

    

3. What is the output of this code? Explain the difference between the two approaches. Any errors?

   # Approach 1
   print(a = 7)
   
   # Approach 2
   print(a := 7)
   

    

4. Identify and fix the error in this code. Can you fix this by adding just one more character?

   while input_str = input("Enter text: "):
       print(input_str)
   

    

5. Explain the difference between the // operator and int for division truncation.

   >>> 2.9 // 1
   >>> int(2.9 / 1)
   >>> -2.9 // 1
   >>> int(-2.9 / 1)
   

    

6. What will be the type and value of each result?

   a = 5 / 2
   b = 5 // 2
   c = int(5 / 2)
   

    

7. What are the results of rounding these numbers? Why?

   >>> round(1.7)
   >>> round(2.5)
   >>> round(1.5)
   >>> round(2.6)
   

    

8. Explain the output of these expressions:

   print(bool('False'))
   print(bool(''))
   print(bool(0.0))
   print(bool([]))
   

    

9. What will the output be?

   print("{} {} {}".format("seven", "eight", "nine"))
   

    

10. What will the output be?

    print("{0} is the first, {1} is the second, and {0} is the first again".format("one", "two"))
    

     

11. What will the output be?

    print("{0}, {val1}, and {1}.".format("the penguin borrowed a ladder", "the kangaroo came by for a smoke", val1="the otter mugged me"))
    

     

12. What will the output be?

    print("{1} {0} {val1}".format("the penguin borrowed a ladder", "the kangaroo came by for a smoke", val1="the otter mugged me"))