6.11. Chapter Assessment

Check your understanding

What will the output be for the following code?

let = "z"
let_two = "p"
c = let_two + let
m = c*5
print(m)

• zpzpzpzpzp
• The order of concatenation matters.
• zzzzzppppp
• Think about the order that the program is executed in, what occurs first?
• pzpzpzpzpz
• Yes, because let_two was put before let, c has "pz" and then that is repeated five times.
• pppppzzzzz
• Think about the order that the program is executed in, what occurs first?
• None of the above, an error will occur.
• This is correct syntax and no errors will occur.

Write a program that extracts the last three items in the list sports and assigns it to the variable last. Make sure to write your code so that it works no matter how many items are in the list.

sports = ['cricket', 'football', 'volleyball', 'baseball', 'softball', 'track and field', 'curling', 'ping pong', 'hockey'] ==== from unittest.gui import TestCaseGui import re class myTests(TestCaseGui): def test_output(self): self.assertEqual(last, ['curling', 'ping pong', 'hockey'], "Testing that the value of last is the last three items in sports.") self.assertTrue(re.search(r'last\s*=\s*\S*3:', self.getEditorText()), "Hardcode check") myTests().main()

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Write code that combines the following variables so that the sentence “You are doing a great job, keep it up!” is assigned to the variable message. Do not edit the values assigned to by, az, io, or qy.

by = "You are" az = "doing a great " io = "job" qy = "keep it up!" ==== from unittest.gui import TestCaseGui class myTests(TestCaseGui): def test_output(self): self.assertEqual(by, 'You are', "Testing original variables.") self.assertEqual(az, 'doing a great ', "Testing original variables.") self.assertEqual(io, 'job', "Testing original variables.") self.assertEqual(qy, 'keep it up!', "Testing original variables.") self.assertEqual(message, 'You are doing a great job, keep it up!', "Testing that the value of message is what was expected.") self.assertNotIn("You are doing a great job, keep it up!", self.getEditorText(), "Testing for hardcoding (Don't worry about actual and expected values).") myTests().main()

What will the output be for the following code?

ls = ['run', 'world', 'travel', 'lights', 'moon', 'baseball', 'sea']
new = ls[2:4]
print(new)

• ['travel', 'lights', 'moon']
• When we take a slice of something, it includes the item at the first index and excludes the item at the second index.
• ['world', 'travel', 'lights']
• When we take a slice of something, it includes the item at the first index and excludes the item at the second index. Additionally, Python is a zero-index based language.
• ['travel', 'lights']
• Yes, python is a zero-index based language and slices are inclusive of the first index and exclusive of the second.
• ['world', 'travel']
• Python is a zero-index based language.

What is the type of m?

l = ['w', '7', 0, 9]
m = l[1:2]

• string
• Not quite, is it slicing or accessing an element?
• integer
• What is happening in the assignment statement for m?
• float
• What is happening in the assignment statement for m?
• list
• Yes, a slice returns a list no matter how large the slice.

What is the type of m?

l = ['w', '7', 0, 9]
m = l[1]

• string
• Yes, the quotes around the number mean that this is a string.
• integer
• Not quite, look again at what is being extracted.
• float
• Not quite, look again at what is being extracted.
• list
• Not quite, is it slicing or accessing an element?

What is the type of x?

b = "My, what a lovely day"
x = b.split(',')

• string
• Not quite; .split() returns a list, each of whose elements is a string.
• integer
• Not quite, look again at what types are present and what the result of .split() is.
• float
• Not quite, look again at what types are present and what the result of .split() is.
• list
• Yes, the .split() method returns a list.

What is the type of a?

b = "My, what a lovely day"
x = b.split(',')
z = "".join(x)
y = z.split()
a = "".join(y)

• string
• Yes, the string is split into a list, then joined back into a string, then split again, and finally joined back into a string.
• integer
• Not quite, look again at what types are present and what the result of .split() is.
• float
• Not quite, look again at what types are present and what the result of .split() is.
• list
• Not quite, think about what .split() and .join() return.

Write code to determine how many 9’s are in the list nums and assign that value to the variable how_many. Do not use a for loop to do this.

nums = [4, 2, 23.4, 9, 545, 9, 1, 234.001, 5, 49, 8, 9 , 34, 52, 1, -2, 9.1, 4] ==== from unittest.gui import TestCaseGui import re class myTests(TestCaseGui): def test_output(self): self.assertEqual(how_many, 3, "Testing that how_many is set correctly.") self.assertNotIn('for', self.getEditorText(), "Testing that you didn't use a for loop.") self.assertFalse(re.search(r'how_many\s*=\s*3', self.getEditorText()), "Hardcode check") myTests().main()

Write code that uses slicing to get rid of the the second 8 so that here are only two 8’s in the list bound to the variable nums.

nums = [4, 2, 8, 23.4, 8, 9, 545, 9, 1, 234.001, 5, 49, 8, 9 , 34, 52, 1, -2, 9.1, 4] ==== from unittest.gui import TestCaseGui import re class myTests(TestCaseGui): def test_output(self): self.assertEqual(nums, [4, 2, 8, 23.4, 9, 545, 9, 1, 234.001, 5, 49, 8, 9 , 34, 52, 1, -2, 9.1, 4], "Testing that nums is set correctly.") self.assertTrue(re.search(r'\s*:', self.getEditorText()), "Testing that you are using slices to remove the second 8 (Don't worry about actual and expected values)") myTests().main()

Assign the last element of lst to the variable end_elem. Do this so that it works no matter how long lst is.

lst = ["hi", "goodbye", "python", "106", "506", 91, ['all', 'Paul', 'Jackie', "UMSI", 1, "Stephen", 4.5], 109, "chair", "pizza", "wolverine", 2017, 3.92, 1817, "account", "readings", "papers", 12, "facebook", "twitter", 193.2, "snapchat", "leaders and the best", "social", "1986", 9, 29, "holiday", ["women", "olympics", "gold", "rio", 21, "2016", "men"], "26trombones"] ==== from unittest.gui import TestCaseGui import re class myTests(TestCaseGui): def testOne(self): self.assertEqual(end_elem, lst[-1], "Testing that end_elem has the correct element assigned.") self.assertFalse(re.search(r'end_elem\s*=\s*\S26trombones\S', self.getEditorText()), "Hardcoding Check (Don't worry about actual and expected values)") myTests().main()

Assign the number of elements in lst to the variable num_lst.

lst = ["hi", "goodbye", "python", "106", "506", 91, ['all', 'Paul', 'Jackie', "UMSI", 1, "Stephen", 4.5], 109, "chair", "pizza", "wolverine", 2017, 3.92, 1817, "account", "readings", "papers", 12, "facebook", "twitter", 193.2, "snapchat", "leaders and the best", "social", "1986", 9, 29, "holiday", ["women", "olympics", "gold", "rio", 21, "2016", "men"], "26trombones"] ==== from unittest.gui import TestCaseGui import re class myTests(TestCaseGui): def testOne(self): self.assertEqual(num_lst, 30, "Testing that num_lst has the correct length assigned.") self.assertFalse(re.search(r'num_lst\s*=\s*30', self.getEditorText()), "Hardcoding Check (Don't worry about actual and expected values)") myTests().main()

Create a variable called wrds and assign to it a list whose elements are the words in the string sent. Do not worry about punctuation.

sent = "The bicentennial for our university was in 2017" ==== from unittest.gui import TestCaseGui import re class myTests(TestCaseGui): def testOne(self): self.assertEqual(wrds, sent.split(), "Testing that wrds has been correctly assigned.") self.assertFalse(re.search(r'wrds\s*=\s*\S*The\S', self.getEditorText()), "Hardcoding Check (Don't worry about actual and expected values)") myTests().main()

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