Chapter 16 Exercises

1. Fix syntax 6 errors in the code below so that the code runs correctly. It should set combined to the concatenation of start and name. It should print the length of the combined string, print the combined string, and it should print the result of name * 3.

   name = 'Mark" start = "My name is ' combined = start name print(len(combined) print(combined) print name * 3

   Change the first ' to a " in line 1. Change the " to a ' in line 2. Add a + after start in line 3. Add a ) at the end of line 4. Add a ( and ) on line 6.

   name = "Mark" start = 'My name is ' combined = start + name print(len(combined)) print(combined) print(name * 3)

   Show Comments

2. Add code to line 1 so that the code below prints 14.

   aString = bString = "bow" cString = (aString + bString) * 2 print(len(cString))

   aString can be any 4 character string

   aString = "rain" bString = "bow" cString = (aString + bString) * 2 print(len(cString))

   Show Comments

3. Fix the 5 syntax errors in the code below so that it runs. It should print the length of myFirstList and print the result of myFirstList * 3. Then it should set mySecondList to the concatenation of myFirstList and a list containing 321.4. Then it should print the value of mySecondList.

   myFirstList = [12,"ape"13] print(len(myFirstList) print(myfirstList * 3) mySecondList = myFirstList + [321.4 print(mySecondList

   Add a comma before the 13 on line 1. Add a ) at the end of line 2. Change line 3 to myFirstList. Add a ] at the end of line 4. Add a ) at the end of line 5.

   myFirstList = [12,"ape",13] print(len(myFirstList)) print(myFirstList * 3) mySecondList = myFirstList + [321.4] print(mySecondList)

   Show Comments

4. Fix the errors so that the procedure prints “My name is JohnJohn” and “19”.

   def nameProcedure(name): start = "My name is" combined = start * (name * 2) print(combined) print(len(combined) nameProcedure(John)

   Add quotations around John on line 8. Add a space after “is” in line 2. In line 3, change the * after start to a +. In line 5 add a ) after combined. Indent lines 2 through 5.

   def nameProcedure(name): start = "My name is " combined = start + (name * 2) print(combined) print(len(combined)) nameProcedure("John")

   Show Comments

5. Fix 5 syntax errors in the code below so that it runs and prints the contents of items.

   def itemLister(items): items[0] = "First item' items[1] = items0] items[2] = items[2] + 1 print items itemLister([2,4,6 8])

   Add a , between 6 and 8 on line 7. Change the ' to a " on line 2. Put a [ before the 0 on line 3. Add ( before items and ) after on line 5.

   def itemLister(items): items[0] = "First item" items[1] = items[0] items[2] = items[2] + 1 print(items) itemLister([2,4,6,8])

   Show Comments

6. Complete the code on lines 4 and 5 so that the function returns the average of a list of integers.

   def gradeAverage(aList): sum = 0 for num in aList: average = return average aList = [99, 100, 74, 63, 100, 100] print(gradeAverage(aList))

   On line 4, add sum = sum + num and on line 5, add sum/ len(aList).

   def gradeAverage(aList): sum = 0 for num in aList: sum = sum + num average = sum / len(aList) return average aList = [99, 100, 74, 63, 100, 100] print(gradeAverage(aList))

   Show Comments

7. Fix the indention in the code below so that it runs correctly. It should loop and add the current value of source to soFar each time through the loop. It should also print the value of soFar each time through the loop.

   source = ["This","is","a","list"] soFar = [] for index in range(0,len(source)): soFar = [source[index]] + soFar print(soFar)

   Indent lines 4 and 5 as shown below.

   source = ["This","is","a","list"] soFar = [] for index in range(0,len(source)): soFar = [source[index]] + soFar print(soFar)

   Show Comments

8. Fix the code so that the code prints “[‘hihi’, 0, 0, 4]” .

   items = ["hi" 2, 3, 4] items[0] = items[0] * items0 items(1) = items[2] - 3 items[2] = items[1] print(items)

   On line 1, add a , before “2”. On line 2, it should be items[0] and a + instead of a *. On line 3, it should be items[1].

   items = ["hi", 2, 3, 4] items[0] = items[0] + items[0] items[1] = items[2] - 3 items[2] = items[1] print(items)

   Show Comments

9. Fix 4 syntax errors in the code below. After the code executes the list soFar should contain the reverse of the source list.

   # setup the source list source = ["This","is" "a","list"] # Set the accumulator to the empty list soFar = [ # Loop through all the items in the source list for index in range(0,len(source)) # Add the current item in the source and print the current items in soFar soFar = [source[index]] + sofar print(soFar)

   Add a comma between is and a on line 2. Add a ] at the end of line 5. Add a : at the end of line 8. Change line 11 to soFar.

   # setup the source list source = ["This","is","a","list"] # Set the accumulator to the empty list soFar = [] # Loop through all the items in the source list for index in range(0,len(source)): # Add the current item in the source and print the current items in soFar soFar = [source[index]] + soFar print(soFar)

   Show Comments

10. The code below currently prints the reverse of a list. Change it so that it prints a mirrored version of the list. It should print “[‘list’, ‘a’, ‘is’, ‘This’, ‘This’, ‘is’, ‘a’, ‘list’]”.

    # setup the source list source = ["This","is","a","list"] # Set the accumulator to the empty list soFar = [] # Loop through all the items in the source list for index in range(0,len(source)): # Add a list with the current item from source to soFar soFar = [source[index]] + soFar print(soFar)

    In the for loop make soFar equal to [source[index]] + soFar + [source[index]].

    # setup the source list source = ["This","is","a","list"] # Set the accumulator to the empty list soFar = [] # Loop through all the items in the source list for index in range(0,len(source)): # Add the lists with the current item from source to soFar soFar = [source[index]] + soFar + [source[index]] print(soFar)

    Show Comments

11. Change the following code into a function. It should take the list and return a list of the values at the even indicies.

    numbers = [0,1,2,3,4,5,6,7,8,9,10] evenList = [] for index in range(0,len(numbers),2): evenList = evenList + [numbers[index]] print(evenList)

    Define a function that takes a list and then call the function and pass in the list. Print the result.

    def getEvenIndicesList(numbers): evenList = [] for index in range(0,len(numbers),2): evenList = evenList + [numbers[index]] return(evenList) print(getEvenIndicesList([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]))

    Show Comments

12. The following code creates and prints a list of even numbers. Change it and add to it so that it creates a list of all multiples of 5 from 0 to 50, inclusive.

    # initialize the variables numbers = [0,1,2,3,4,5,6,7,8,9,10] evens = [] # loop though every other index for index in range(0,len(numbers),2): # add the lists evens = evens + [numbers[index]] # print the result print(evens)

    Change numbers to equal range(1,51,5) and the range in the for loop to (0,len(numbers)).

    # initialize the variables numbers = range(1,51,5) fives = [] # loop though every index for index in range(0,len(numbers)): # add the lists fives = fives + [numbers[index]] # print the result print(fives)

    Show Comments

13. Change the following into a procedure. It prints a countdown from 5 to 0. Have it take the starting number for the countdown as a parameter. Print each value till it gets to 0.

    for index in range(5, -1, -1): print(index)

    Define the procedure and call it. Be sure to pass the number to start the countdown at.

    def countdown(start): for index in range(start, -1, -1): print(index) countdown(10)

    Show Comments

14. Fix the errors so that the code individually adds each item from source to newList. Make the range decrement, so it starts from the end, but keep newList in the same order as source.

    # initialize the variables source = ["This","is","a","list"] newList = [] # loop from the last index to the first (0) for index in range(len(source), 1, -1): # append the lists newList = newList + [source[index]] # print the current value of the list print(newList)

    On line 6, the range should be (len(source) - 1, -1, -1). Indent line 9 and switch the order the items are added.

    # initialize the variables source = ["This","is","a","list"] newList = [] # loop from the last index to the first (0) for index in range(len(source) - 1, -1, -1): # append the lists newList = [source[index]] + newList # print the current value of the list print(newList)

    Show Comments

15. Write a function that returns the values at the odd indices in a list. The function should take the number list as a parameter. If it is passed [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10] for example, it should return [1, 3, 5, 7, 9].

    See the function below. Be sure to create the function and call it and print the result.

    def getOddIndicesList(numbers): evenList = [] for index in range(1,len(numbers),2): evenList = evenList + [numbers[index]] return(evenList) print(getOddIndicesList([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]))

    Show Comments

16. Write a function that takes a list of numbers as a parameter and adds 5 to each number and returns the list.

    You need to know the index of each item in the list so use the range function in the for loop.

    def listAdder(aList): for x in range(len(aList)): aList[x] = aList[x] + 5 return aList nums = [1,2,3] print(listAdder(nums))

    Show Comments

17. Write a function that takes a list of numbers and returns the sum of the positive numbers in the list.

    Define the function as shown below. Be sure to accumulate and return the sum. Call the function and print the result.

    def sumPos(theList): sum = 0 for item in theList: if item >= 0: sum = sum + item return sum print(sumPos([-3, 2, -8, 5, -20, -33, 15]))

    Show Comments

18. Write a function that takes in a list of numbers as a parameter. The function should calculate the sum of all the positive numbers in the list, the absolute value of the sum of the negative numbers, and return the average of the two sums.

    Define the function as shown below.

    def aFunction(aList): posSum = 0 negSum = 0 for x in aList: if x >= 0: posSum = posSum + x else: negSum = negSum + x avg = (posSum + (negSum * -1))/2 return avg nums = [-3,-1,2,4] print(aFunction(nums))

    Show Comments

19. Write a function to return the reverse of a list, but with only every other item from the original list starting at the end of the list. So, if it is passed the list [0,1,2,3,4,5] for example, it should return the list [5, 3, 1].

    Define the function as shown below.

    def reverseEveryOther(theList): newList = [] for index in range(len(theList) - 1, -1, -2): newList = newList + [theList[index]] return newList print(reverseEveryOther([0,1,2,3,4,5]))

    Show Comments

20. Write a procedure that takes an int as a parameter. The procedure should add every other odd number from 1 to the int parameter (inclusive) into a new list. The procedure should print the new list and the sum of the new list.

    Define the procedure as below.

    def aProcedure(num): newList = [] sum = 0 for i in range(1, num + 1, 4): newList = newList + [i] sum = sum + i print(newList) print(sum) aProcedure(20)

    Show Comments

You have attempted of activities on this page