Chapter 7 - CIS 3389
What will the following code display? numbers = [ 1, 2, 3, 4, 5 ] my_list = numbers[ -3: ] print(my_list)
[3, 4, 5]
Give two reasons why tuples exist.
1. Certain operations in python require a tuple 2. Processing tuples are faster than processing a list.
What will the following code display? numbers = [ 1, 2, 3, 4, 5 ] print(numbers[ -2 ])
4
What will the following code display? numbers = [ 1, 2, 3, 4, 5 ] my_list = numbers[ 1: ] print(my_list)
[2, 3]
What will the following code display? numbers = [ 1, 2, 3, 4, 5 ] my_list = numbers[ 1:3 ] print(my_list)
[2, 3]
What is the primary difference between a list and a tuple?
a tuple is immutable, which means that once it is created, its contents cannot be changed. a list is mutable, which means that a program can change its contents.
Describe the following list method: - index
a) INDEX - searches for an item in the list and returns the index of the first element containing that item
What will the following code display? numbers = list(range( 1, 10, 2 )) for n in numbers: print(n)
1 3 5 7 9
What will the following code display? names = ['Jim', 'Jill', 'John', 'Jasmine'] if 'Jasmine' not in names: print('Cannot find Jasmine.') else: print("Jasmine's family:") print(names)
Jasmine's family: ['Jim', 'Jill', 'John', 'Jasmine']
What is the difference between calling a list's REMOVE method and using the DEL statement to remove an element.
REMOVE searches for and removes an element containing a specific value. DEL statement removes an element at a specific index
How many rows and how many columns are in the list? numbers = [[1, 2], [10, 20], [100, 200], [1000, 2000]]
The list contains 4 rows and 2 columns
Assume the following statement appears in a program: names = [ ] Which of the following statements would you use to add the string 'Wendy' to the list at index 0? Why would you select this statement instead of the other? a. names[0] = 'Wendy' b. names.append('Wendy')
You would use statement b, names.append('Wendy'). This is because element 0 does not exist. If you try to use statement a, an error will occur
What will the following code display? numbers = list(range(3)) prints(numbers)
[0, 1, 2]
What will the following code display? numbers = [ 1, 2, 3, 4, 5 ] my_list = numbers[ : ] print(my_list)
[1, 2, 3, 4, 5]
What will the following code display? numbers1 = [ 1, 2, 3 ] numbers2 = [ 10, 20, 30 ] numbers2 += numbers1 print(numbers1) print(numbers2)
[1, 2, 3] [10, 20, 30, 1, 2, 3]
What will the following code display? numbers1 = [ 1, 2, 3 ] numbers2 = [ 10, 20, 30 ] numbers3 = numbers1 + numbers2 print(numbers1) print(numbers2) print(numbers3)
[1, 2, 3] [10, 20, 30] [1, 2, 3, 10, 20, 30]
What will the following code display? numbers = [ 1, 2, 3, 4, 5 ] numbers[2] = 99 print(numbers)
[1, 2, 99, 4, 5]
What will the following code display? numbers = [10] * 5 print(numbers)
[10, 10, 10, 10, 10]
What will the following code display? numbers = [ 1, 2, 3, 4, 5 ] my_list = numbers[ :1 ] print(my_list)
[1]
How do you find the lowest and highest values in a list?
by using the min and/or the max functions
Write a nested loop that display the contents of the numbers: numbers = [[1, 2], [10, 20], [100, 200], [1000, 2000]]
for r in range(4): for c in range(2): print(numbers[r][c])
Describe the following list method: - insert
inserts an item into the list at a specified index
Write a statement that creates a two-dimensional list with three rows and four columns. Each element should be assigned the value 0.
my list = [[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0]]
Assume that my_tuple references a tuple. Write a statement that converts it to a list.
my_list = list(my_tuple)
Assume that my_list references a list. Write a statement that converts it to a tuple.
my_tuple = tuple(my_list)
Describe the following list method: - reverse
reverses the order of the items in the list
Describe the following list method: - sort
sorts the items in the list to appear in ascending order
How do you find the elements in a list?
use the built-in *len* function
