booleans

what are booleans?

There are only 2 booleans - True and False. I can use the assertFalse and assertTrue methods to test which of the basic data structures seen so far - integers, floats, strings, tuples, lists, sets and dictionaries, are True or False in Python

preview

Here are the tests I have by the end of the chapter

 1import unittest
 2
 3
 4class TestBooleans(unittest.TestCase):
 5
 6    def test_what_is_false(self):
 7        self.assertIsInstance(False, bool)
 8        self.assertFalse(False)
 9        self.assertFalse(None)
10        self.assertFalse(0)
11        self.assertFalse(0.0)
12        self.assertFalse(str())
13        self.assertFalse(tuple())
14        self.assertFalse(list())
15        self.assertFalse(set())
16        self.assertFalse(dict())
17
18    def test_what_is_true(self):
19        self.assertIsInstance(True, bool)
20        self.assertTrue(True)
21        self.assertTrue(-1)
22        self.assertTrue(1)
23        self.assertTrue(-0.1)
24        self.assertTrue(0.1)
25        self.assertTrue('text')
26        self.assertTrue((1, 2, 3, 'n'))
27        self.assertTrue([1, 2, 3, 'n'])
28        self.assertTrue({1, 2, 3, 'n'})
29        self.assertTrue({'key': 'value'})
30
31
32# NOTES
33# a dictionary with things is true
34# a set with things is true
35# a list with things is true
36# a tuple with things is true
37# a string with things is true
38# positive and negative numbers are true
39# True is true
40# True is not false
41# True is a boolean
42# the empty dictionary is false
43# the empty set is false
44# the empty list is false
45# the empty tuple is false
46# the empty string is false
47# 0 is false
48# None is false
49# False is false
50# False is not true
51# False is a boolean
52
53
54# Exceptions seen
55# AssertionError

questions about Booleans

Here are the questions you can answer after going through this chapter

start the project

  • I name this project booleans

  • I open a terminal

  • then I make a directory for the project

    mkdir booleans

    the terminal goes back to the command line

    .../pumping_python

  • I change directory to the project

    cd booleans

    the terminal shows I am now in the booleans folder

    .../pumping_python/booleans

  • I make a folder for the source code

    mkdir src

    the terminal goes back to the command line

    .../pumping_python/booleans

  • I use touch to make an empty file for the program in the src folder

    touch src/booleans.py

    on Windows without Windows Subsystem for Linux use New-Item src/booleans.py instead of touch src/booleans.py

    New-Item src/booleans.py

    the terminal goes back to the command line

    .../pumping_python/booleans

  • I make a directory for the tests

    mkdir tests

    the terminal goes back to the command line

  • I use touch to make an empty file in the tests folder to tell Python that it is a Python package

    Attention

    use 2 underscores (__) before and after init for __init__.py not _init_.py

    touch tests/__init__.py

    on Windows without Windows Subsystem for Linux use New-Item tests/__init__.py instead of touch tests/__init__.py

    New-Item tests/__init__.py

    the terminal goes back to the command line

  • I make an empty file for the actual test

    touch tests/test_booleans.py

    on Windows without Windows Subsystem for Linux use New-Item tests/test_booleans.py instead of touch tests/test_booleans.py

    New-Item tests/test_booleans.py

    the terminal goes back to the command line

  • I open test_booleans.py in the editor of the Integrated Development Environment (IDE)

    Tip

    I can open a file from the terminal in Visual Studio Code by typing code and the name of the file with

    code tests/test_booleans.py

    test_booleans.py opens up in the editor

  • I add the first failing test to test_booleans.py

    1import unittest
2
3
4class TestBooleans(unittest.TestCase):
5
6    def test_failure(self):
7        self.assertFalse(True)

  • I make a virtual environment in the terminal

    python3 -m venv .venv

    on Windows without Windows Subsystem for Linux use python3 -m venv .venv instead of python3 -m venv .venv

    python -m venv .venv

    the terminal takes some time then goes back to the command line

  • I activate the virtual environment

    source .venv/bin/activate

    on Windows without Windows Subsystem for Linux use .venv/bin/activate.ps1 instead of source .venv/bin/activate

    .venv/scripts/activate.ps1

    the terminal shows

    (.venv) .../pumping_python/booleans

  • I upgrade the Python package manager (pip) to the latest version

    python3 -m pip install --upgrade pip

    the terminal shows pip being uninstalled then installs the latest version or shows that it is already the latest version

  • I make a requirements.txt file for the Python programs my project needs

    echo "pytest-watch" > requirements.txt

    the terminal goes back to the command line

  • I use pip to use the requirements file to install pytest-watch

    python3 -m pip install --requirement requirements.txt

    on Windows without Windows Subsystem for Linux use python -m pip install --requirement requirements.txt instead of python3 -m pip install --requirement requirements.txt

    python -m pip install --requirement requirements.txt

    the terminal shows pip downloads and installs the Python programs that pytest-watch needs to run

  • I use pytest-watch to run the test

    pytest-watch

    the terminal shows

    ================================ FAILURES ================================
______________________ TestBooleans.test_failure ________________________

self = <tests.test_booleans.TestBooleans testMethod=test_failure>

    def test_failure(self):
>       self.assertFalse(True)
E       AssertionError: True is not false

tests/test_booleans.py:7: AssertionError
======================== short test summary info =========================
FAILED tests/test_booleans.py::TestBooleans::test_failure - AssertionError: True is not false
=========================== 1 failed in X.YZs ============================

  • I hold ctrl (Windows/Linux) or option or command (MacOS) on the keyboard and use the mouse to click on tests/test_booleans.py:7 to open it in the editor

  • I add AssertionError to the list of Exceptions seen in test_booleans.py

     7        self.assertFalse(True)
 8
 9
10# Exceptions seen
11# AssertionError

  • then I change True to False in the assertion

    7        self.assertFalse(False)

    the test passes

test_what_is_false

RED: make it fail

  • I change test_failure to test_what_is_false, then use the assertNotIsInstance method from testing None to check if False is a child/instance of the bool class expecting a failure

    1import unittest
2
3
4class TestBooleans(unittest.TestCase):
5
6    def test_what_is_false(self):
7        self.assertNotIsInstance(False, bool)

    the terminal shows AssertionError

    AssertionError: False is an instance of <class 'bool'>

GREEN: make it pass

I change assertNotIsInstance to assertIsInstance

7        self.assertIsInstance(False, bool)

the test passes and I add a note

10# NOTES
11# False is a boolean
12
13
14# Exceptions seen

so far this is going over what I already know from testing None

test_what_is_true

I do the same thing with True

RED: make it fail

I add another failing test

 6    def test_what_is_false(self):
 7        self.assertIsInstance(False, bool)
 8
 9    def test_what_is_true(self):
10        self.assertNotIsInstance(True, bool)
11
12
13# NOTES

the terminal shows AssertionError

AssertionError: True is an instance of <class 'bool'>

GREEN: make it pass

  • I change the assert method

    10        self.assertIsInstance(True, bool)

    the test passes

  • I add another note

    13# NOTES
14# True is a boolean
15# False is a boolean
16
17
18# Exceptions seen

REFACTOR: make it better

  • I add a failing line to test_what_is_true

     9    def test_what_is_true(self):
10        self.assertIsInstance(True, bool)
11        self.assertTrue(False)
12
13
14# NOTES

    the terminal shows AssertionError

    AssertionError: False is not true

  • I change assertTrue to assertFalse

     9    def test_what_is_true(self):
10        self.assertIsInstance(True, bool)
11        self.assertFalse(False)

    the test passes

  • I add a note

    13# NOTES
14# True is a boolean
15# False is not true
16# False is a boolean
17
18
19# Exceptions seen
20# AssertionError

  • I move the line from test_what_is_true to the test_what_is_false method

     6  def test_what_is_false(self):
 7      self.assertIsInstance(False, bool)
 8      self.assertFalse(False)
 9
10  def test_what_is_true(self):
11      self.assertIsInstance(True, bool)

    Tip

    You do not need to copy and paste to move a line. If you are using Visual Studio Code you can use alt (Windows/Linux) or option (MacOS) with the up/down arrows on the keyboard to move a line up or down

  • I add a note

    14# NOTES
15# True is a boolean
16# False is false
17# False is not true
18# False is a boolean
19
20
21# Exceptions seen

  • I add a failing line to test_what_is_false

    6    def test_what_is_false(self):
7        self.assertIsInstance(False, bool)
8        self.assertFalse(False)
9        self.assertFalse(True)

    the terminal shows AssertionError

    AssertionError: True is not false

  • I change assertFalse to assertTrue

    6    def test_what_is_false(self):
7        self.assertIsInstance(False, bool)
8        self.assertFalse(False)
9        self.assertTrue(True)

    the test passes

  • I add a note

    15# NOTES
16# True is not false
17# True is a boolean
18# False is false
19# False is not true
20# False is a boolean
21
22
23# Exceptions seen

  • I move the line from test_what_is_false to the test_what_is_true method

     6    def test_what_is_false(self):
 7        self.assertIsInstance(False, bool)
 8        self.assertFalse(False)
 9
10    def test_what_is_true(self):
11        self.assertIsInstance(True, bool)
12        self.assertTrue(True)

  • I add another note

    15# NOTES
16# True is true
17# True is not false
18# True is a boolean
19# False is false
20# False is not true
21# False is a boolean
22
23
24# Exceptions seen
25# AssertionError

All of this is still a repetition of what I did with AssertionError. Next up, I test the other Python basic data types to see which of are False or True

is None False or True?

RED: make it fail

I add a line in test_what_is_true to test if None is True

10    def test_what_is_true(self):
11        self.assertIsInstance(True, bool)
12        self.assertTrue(True)
13        self.assertTrue(None)

the terminal shows AssertionError

AssertionError: None is not true

GREEN: make it pass

I change the method

13        self.assertFalse(None)

the test passes

REFACTOR: make it better

I move the line from test_what_is_true to test_what_is_false

 6    def test_what_is_false(self):
 7        self.assertIsInstance(False, bool)
 8        self.assertFalse(False)
 9        self.assertFalse(None)
10
11    def test_what_is_true(self):
12        self.assertIsInstance(True, bool)
13        self.assertTrue(True)

I add a note

16# NOTES
17# True is true
18# True is not false
19# True is a boolean
20# None is false
21# False is false
22# False is not true
23# False is a boolean
24
25
26# Exceptions seen

None is False though I learned in test_assertion_error_w_false that False is not None

is an integer False or True?

RED: make it fail

I add a failing line test_what_is_false to see if an integer (a whole number) is False

 6    def test_what_is_false(self):
 7        self.assertIsInstance(False, bool)
 8        self.assertFalse(False)
 9        self.assertFalse(None)
10        self.assertFalse(-1)
11
12    def test_what_is_true(self):

the terminal shows AssertionError

AssertionError: -1 is not false

GREEN: make it pass

I change the method

10        self.assertTrue(-1)

the test passes

REFACTOR: make it better

  • I move the line from test_what_is_false to test_what_is_true

     6    def test_what_is_false(self):
 7        self.assertIsInstance(False, bool)
 8        self.assertFalse(False)
 9        self.assertFalse(None)
10
11    def test_what_is_true(self):
12        self.assertIsInstance(True, bool)
13        self.assertTrue(True)
14        self.assertTrue(-1)

    I use -1 for all the integers (whole numbers) that are smaller than 0. Negative integers are True in Python

  • I add a new failing line to test_what_is_true to see if 0 is True

    14        self.assertTrue(-1)
15        self.assertTrue(0)

    the terminal shows AssertionError

    AssertionError: 0 is not true

  • I change the method to assertFalse

    15        self.assertFalse(0)

    the test passes

  • I move the line to test_what_is_false

     7        self.assertIsInstance(False, bool)
 8        self.assertFalse(False)
 9        self.assertFalse(None)
10        self.assertFalse(0)
11
12    def test_what_is_true(self):

    0 is False in Python

  • I add another failing line to test_what_is_false to see if 1 is False

    10        self.assertFalse(0)
11        self.assertFalse(1)
12
13    def test_what_is_true(self):
14        self.assertIsInstance(True, bool)

    the terminal shows AssertionError

    AssertionError: 1 is not false

  • I change the method

    11        self.assertTrue(1)

    the test passes

  • I move the line to test_what_is_true

    10        self.assertFalse(0)
11
12    def test_what_is_true(self):
13        self.assertIsInstance(True, bool)
14        self.assertTrue(True)
15        self.assertTrue(-1)
16        self.assertTrue(1)

    I use 1 for all the integers (whole numbers) that are bigger than 0. Positive and negative integers are True in Python

  • I add notes

    19# NOTES
20# positive and negative integers are true
21# True is true
22# True is not false
23# True is a boolean
24# 0 is false
25# None is false
26# False is false
27# False is not true
28# False is a boolean
29
30
31# Exceptions seen
32# AssertionError

is a float False or True?

RED: make it fail

I add a line to test if floats (binary floating point decimal numbers) are False in test_what_is_false

10        self.assertFalse(0)
11        self.assertFalse(-0.1)
12
13    def test_what_is_true(self):

the terminal shows AssertionError

AssertionError: -0.1 is not false

GREEN: make it pass

  • I change the method

    11        self.assertTrue(-0.1)

    the test passes

  • I move the line to test_what_is_true

    14        self.assertTrue(True)
15        self.assertTrue(-1)
16        self.assertTrue(1)
17        self.assertTrue(-0.1)

    I use -0.1 for all the floating point numbers that are smaller than 0.0. Negative floats are True in Python

REFACTOR: make it better

  • I add another failing line to test_what_is_true to see if 0.0 is True

    17        self.assertTrue(-0.1)
18        self.assertTrue(0.0)

    the terminal shows AssertionError

    AssertionError: 0.0 is not true

    I change the method

    18        self.assertFalse(0.0)

    the test passes

  • I move the line to test_what_is_false

     7    def test_what_is_false(self):
 8        self.assertIsInstance(False, bool)
 9        self.assertFalse(False)
10        self.assertFalse(None)
11        self.assertFalse(0)
12        self.assertFalse(0.0)
13
14    def test_what_is_true(self):

    0.0 is False in Python

  • I add another line to test_what_is_false to see if 0.1 is False in Python

    11        self.assertFalse(0.0)
12        self.assertFalse(0.1)
13
14    def test_what_is_true(self):
15        self.assertIsInstance(True, bool)

    the terminal shows AssertionError

    AssertionError: 0.1 is not false

  • I change the method

    15        self.assertTrue(0.1)

    the test passes

  • I move the line to test_what_is_true

    11        self.assertFalse(0.0)
12
13    def test_what_is_true(self):
14        self.assertIsInstance(True, bool)
15        self.assertTrue(True)
16        self.assertTrue(-1)
17        self.assertTrue(1)
18        self.assertTrue(-0.1)
19        self.assertTrue(0.1)
20
21
22# NOTES

    I use 0.1 for all the floating point numbers that are bigger than 0.0. Positive and negative floats are also True in Python

  • I add notes

    22# NOTES
23# positive and negative floats are true
24# positive and negative integers are true
25# True is true
26# True is not false
27# True is a boolean
28# 0.0 is false
29# 0 is false
30# None is false
31# False is false
32# False is not true
33# False is a boolean

  • I make the new notes simpler because floats and integers are numbers and 0.0 is the same as 0 even though they are different types

    22# NOTES
23# positive and negative numbers are true
24# True is true
25# True is not false
26# True is a boolean
27# 0 is false
28# None is false
29# False is false
30# False is not true
31# False is a boolean
32
33
34# Exceptions seen

is a string False or True?

RED: make it fail

I add a failing line to test_what_is_true to test if a string (anything in quotes) is True

13    def test_what_is_true(self):
14        self.assertIsInstance(True, bool)
15        self.assertTrue(True)
16        self.assertTrue(-1)
17        self.assertTrue(1)
18        self.assertTrue(-0.1)
19        self.assertTrue(0.1)
20        self.assertTrue(str())
21
22
23# NOTES

the terminal shows AssertionError

AssertionError: '' is not true

the empty string (‘’) is not True

GREEN: make it pass

I change the method

20        self.assertFalse(str())

the test passes

REFACTOR: make it better

  • I move the line to test_what_is_false

    11        self.assertFalse(0.0)
12        self.assertTrue(str())
13
14    def test_what_is_true(self):

    the empty string (‘’) is not False

  • I add a failing line to test_what_is_false

    11        self.assertFalse(0.0)
12        self.assertFalse(str())
13        self.assertFalse('text')

    the terminal shows AssertionError

    AssertionError: 'text' is not false

    I change the method

    13        self.assertTrue('text')

    the test passes

  • I move the line to test_what_is_true

    12        self.assertFalse(str())
13
14    def test_what_is_true(self):
15        self.assertIsInstance(True, bool)
16        self.assertTrue(True)
17        self.assertTrue(-1)
18        self.assertTrue(1)
19        self.assertTrue(-0.1)
20        self.assertTrue(0.1)
21        self.assertTrue('text')
22
23
24# NOTES

  • I add notes

    24# NOTES
25# a string with things is true
26# positive and negative numbers are true
27# True is true
28# True is not false
29# True is a boolean
30# the empty string is false
31# 0 is false
32# None is false
33# False is false
34# False is not true
35# False is a boolean
36
37
38# Exceptions seen
39# AssertionError

is a tuple False or True?

RED: make it fail

I add a line to test_what_is_true to see if a tuple (anything in parentheses (())) is True

14    def test_what_is_true(self):
15        self.assertIsInstance(True, bool)
16        self.assertTrue(True)
17        self.assertTrue(-1)
18        self.assertTrue(1)
19        self.assertTrue(-0.1)
20        self.assertTrue(0.1)
21        self.assertTrue('text')
22        self.assertTrue(tuple())
23
24
25# NOTES

The terminal shows AssertionError

AssertionError: () is not true

the empty tuple is not True

GREEN: make it pass

  • I change the assert method

    22        self.assertFalse(tuple())

    the test passes

  • I move the line to test_what_is_false

     6    def test_what_is_false(self):
 7        self.assertIsInstance(False, bool)
 8        self.assertFalse(False)
 9        self.assertFalse(None)
10        self.assertFalse(0)
11        self.assertFalse(0.0)
12        self.assertFalse(str())
13        self.assertFalse(tuple())
14
15    def test_what_is_true(self):

REFACTOR: make it better

  • I add another line to test_what_is_false to see if a tuple with things is False

    13        self.assertFalse(tuple())
14        self.assertFalse((1, 2, 3, 'n'))

    the terminal shows AssertionError

    AssertionError: (1, 2, 3, 'n') is not false

    a tuple with things is NOT False

  • I change the method

    14        self.assertTrue((1, 2, 3, 'n'))

    the test passes

  • I move the line to test_what_is_true

    13        self.assertFalse(tuple())
14
15    def test_what_is_true(self):
16        self.assertIsInstance(True, bool)
17        self.assertTrue(True)
18        self.assertTrue(-1)
19        self.assertTrue(1)
20        self.assertTrue(-0.1)
21        self.assertTrue(0.1)
22        self.assertTrue('text')
23        self.assertTrue((1, 2, 3, 'n'))
24
25
26# NOTES

    Tip

    If you are using Visual Studio Code you can use alt (Windows/Linux) or option (MacOS) with the up/down arrows on the keyboard to move a line up or down

  • I add notes

    26# NOTES
27# a tuple with things is true
28# a string with things is true
29# positive and negative numbers are true
30# True is true
31# True is not false
32# True is a boolean
33# the empty tuple is false
34# the empty string is false
35# 0 is false
36# None is false
37# False is false
38# False is not true
39# False is a boolean

is a list False or True?

RED: make it fail

I add a line to test if a list (anything in square brackets ([])) is True

23    self.assertTrue((1, 2, 3, 'n'))
24    self.assertTrue(list())

the terminal shows AssertionError

AssertionError: [] is not true

the empty list is NOT True

GREEN: make it pass

  • I change the method

    24        self.assertFalse(list())

    the test passes

  • I move the line to test_what_is_false

    13        self.assertFalse(tuple())
14        self.assertFalse(list())
15
16    def test_what_is_true(self):

REFACTOR: make it better

  • I add another line to test_what_is_false to see if a list with things is False

    14        self.assertFalse(list())
15        self.assertFalse([1, 2, 3, 'n'])
16
17    def test_what_is_true(self):
18        self.assertIsInstance(True, bool)

    the terminal shows AssertionError

    AssertionError: [1, 2, 3, 'n'] is not false

  • I change the method

    15        self.assertTrue([1, 2, 3, 'n'])

    the test passes

  • I move the line to test_what_is_true

    14        self.assertFalse(list())
15
16    def test_what_is_true(self):
17        self.assertIsInstance(True, bool)
18        self.assertTrue(True)
19        self.assertTrue(-1)
20        self.assertTrue(1)
21        self.assertTrue(-0.1)
22        self.assertTrue(0.1)
23        self.assertTrue('text')
24        self.assertTrue((1, 2, 3, 'n'))
25        self.assertTrue([1, 2, 3, 'n'])
26
27
28# NOTES

  • I add notes

    28# NOTES
29# a list with things is true
30# a tuple with things is true
31# a string with things is true
32# positive and negative numbers are true
33# True is true
34# True is not false
35# True is a boolean
36# the empty list is false
37# the empty tuple is false
38# the empty string is false
39# 0 is false
40# None is false
41# False is false
42# False is not true
43# False is a boolean
44
45
46# Exceptions seen
47# AssertionError

I can see a pattern forming

is a set False or True?

RED: make it fail

I add a line to in test_what_is_true to see if a set is True

25        self.assertTrue([1, 2, 3, 'n'])
26        self.assertTrue(set())
27
28
29# NOTES

the terminal shows AssertionError

AssertionError: set() is not true

the empty set is NOT True

GREEN: make it pass

  • I change the method

    26        self.assertFalse(set())

    the test passes

  • I move the line to test_what_is_false

    14        self.assertFalse(list())
15        self.assertFalse(set())
16
17    def test_what_is_true(self):

REFACTOR: make it better

  • I add another line to test_what_is_false to see if a set with things is False

    15        self.assertFalse(set())
16        self.assertFalse({1, 2, 3, 'n'})
17
18    def test_what_is_true(self):

    the terminal shows AssertionError

    AssertionError: {1, 2, 3, 'n'} is not false

    a set with things is NOT False

  • I change the method

    16        self.assertTrue({1, 2, 3, 'n'})

    the test passes

  • I move the line to test_what_is_true

    15        self.assertFalse(set())
16
17    def test_what_is_true(self):
18        self.assertIsInstance(True, bool)
19        self.assertTrue(True)
20        self.assertTrue(-1)
21        self.assertTrue(1)
22        self.assertTrue(-0.1)
23        self.assertTrue(0.1)
24        self.assertTrue('text')
25        self.assertTrue((1, 2, 3, 'n'))
26        self.assertTrue([1, 2, 3, 'n'])
27        self.assertTrue({1, 2, 3, 'n'})
28
29
30# NOTES

  • I add to the notes

    30# NOTES
31# a set with things is true
32# a list with things is true
33# a tuple with things is true
34# a string with things is true
35# positive and negative numbers are true
36# True is true
37# True is not false
38# True is a boolean
39# the empty set is false
40# the empty list is false
41# the empty tuple is false
42# the empty string is false
43# 0 is false
44# None is false
45# False is false
46# False is not true
47# False is a boolean
48
49
50# Exceptions seen
51# AssertionError

is a dictionary False or True?

RED: make it fail

I add a line to test_what_is_true to test if a dictionary is True

27        self.assertTrue({1, 2, 3, 'n'})
28        self.assertTrue(dict())
29
30
31# NOTES

the terminal shows AssertionError

AssertionError: {} is not true

the empty dictionary is NOT True

GREEN: make it pass

  • I change assertTrue to assertFalse

    28        self.assertFalse(dict())

    the test passes

  • I move the line to the test_what_is_false method

     6    def test_what_is_false(self):
 7        self.assertIsInstance(False, bool)
 8        self.assertFalse(False)
 9        self.assertFalse(None)
10        self.assertFalse(0)
11        self.assertFalse(0.0)
12        self.assertFalse(str())
13        self.assertFalse(tuple())
14        self.assertFalse(list())
15        self.assertFalse(set())
16        self.assertFalse(dict())
17
18    def test_what_is_true(self):

REFACTOR: make it better

  • I add another line to test if a dictionary with things is also False

    14        self.assertFalse(list())
15        self.assertFalse(set())
16        self.assertFalse(dict())
17        self.assertFalse({'key': 'value'})

    the terminal shows AssertionError

    AssertionError: {'key': 'value'} is not false

    a dictionary with things is NOT False

  • I change assertFalse to assertTrue

    17        self.assertTrue({'key': 'value'})

    the test passes

  • I move the line to the test_what_is_true method

     6    def test_what_is_false(self):
 7        self.assertIsInstance(False, bool)
 8        self.assertFalse(False)
 9        self.assertFalse(None)
10        self.assertFalse(0)
11        self.assertFalse(0.0)
12        self.assertFalse(str())
13        self.assertFalse(tuple())
14        self.assertFalse(list())
15        self.assertFalse(set())
16        self.assertFalse(dict())
17
18    def test_what_is_true(self):
19        self.assertIsInstance(True, bool)
20        self.assertTrue(True)
21        self.assertTrue(-1)
22        self.assertTrue(1)
23        self.assertTrue(-0.1)
24        self.assertTrue(0.1)
25        self.assertTrue('text')
26        self.assertTrue((1, 2, 3, 'n'))
27        self.assertTrue([1, 2, 3, 'n'])
28        self.assertTrue({1, 2, 3, 'n'})
29        self.assertTrue({'key': 'value'})
30
31
32# NOTES

  • I add the last 2 notes

    32# NOTES
33# a dictionary with things is true
34# a set with things is true
35# a list with things is true
36# a tuple with things is true
37# a string with things is true
38# positive and negative numbers are true
39# True is true
40# True is not false
41# True is a boolean
42# the empty dictionary is false
43# the empty set is false
44# the empty list is false
45# the empty tuple is false
46# the empty string is false
47# 0 is false
48# None is false
49# False is false
50# False is not true
51# False is a boolean
52
53
54# Exceptions seen
55# AssertionError

close the project

  • I close the file(s) I have open in the editor(s)

  • I click in the terminal and exit the tests with ctrl+c on the keyboard

  • I deactivate the virtual environment

    deactivate

    the terminal goes back to the command line, (.venv) is no longer on the left side

    .../pumping_python/booleans

  • I change directory to the parent of booleans

    cd ..

    the terminal shows

    .../pumping_python

    I am back in the pumping_python directory

review

From the tests I can see that in Python

these things come in handy when I write conditions in programs, because I can make decisions on whether the data is empty or has something in it

How many questions can you answer after going through this chapter?

code from the chapter

Do you want to see all the CODE I typed in this chapter?

what is next?

you now know

Would you like to test the truth table? It will help you understand writing programs that make decisions based on conditions

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