what causes AttributeError?

AttributeError happens when a name that is NOT in an object (everything in Python is an object) is used.

what is an attribute?

An attribute is a name (variable?) for something that belongs to an object (a class), for example, a human being has attributes like height, weight, sex and color, they are also known as properties.

preview

I have these tests by the end of the chapter

attribute_error/tests/test_attribute_error.py
 1import src.attribute_error
 2
 3
 4def test_attribute_error_w_variables():
 5    src.attribute_error.variable_00
 6    src.attribute_error.variable_01
 7    src.attribute_error.variable_02
 8    src.attribute_error.variable_03
 9    src.attribute_error.variable_04
10    src.attribute_error.variable_05
11    src.attribute_error.variable_06
12    src.attribute_error.variable_07
13    src.attribute_error.variable_08
14    src.attribute_error.variable_09
15
16
17def test_attribute_error_w_functions():
18    src.attribute_error.function_00()
19    src.attribute_error.function_01()
20    src.attribute_error.function_02()
21    src.attribute_error.function_03()
22    src.attribute_error.function_04()
23    src.attribute_error.function_05()
24    src.attribute_error.function_06()
25    src.attribute_error.function_07()
26    src.attribute_error.function_08()
27    src.attribute_error.function_09()
28
29
30# Exceptions seen
31# AssertionError
32# ModuleNotFoundError
33# AttributeError
34# NameError
35# TypeError

questions about AttributeError

Questions to think about as I go through the chapter

start the project

  • I name this project attribute_error

  • I open a terminal

  • I change directory to the attribute_error folder in the pumping_python folder

    cd attribute_error

    the terminal shows

    cd: no such file or directory: attribute_error

    there is no folder with the name attribute_error in this folder.

  • I use uv to make a directory for the project and initialize it

    uv init attribute_error

    the terminal shows

    Initialized project `attribute-error`
at `.../pumping_python/attribute_error`

    then goes back to the command line.

  • I change directory to the project

    cd attribute_error

    the terminal shows I am in the attribute_error folder

    .../pumping_python/attribute_error

  • I make a directory for the tests

    mkdir tests

    the terminal goes back to the command line.

  • I make the tests directory a Python package

    Danger

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

    touch tests/__init__.py

    New-Item tests/__init__.py

    the terminal goes back to the command line.

  • I make a Python file for the tests in the tests directory

    touch tests/test_attribute_error.py

    New-Item tests/test_attribute_error.py

    the terminal goes back to the command line.

  • I make an empty file for the tests in the tests folder

    touch tests/test_attribute_error.py

    New-Item tests/test_attribute_error.py

    the terminal goes back to the command line.

  • I open test_attribute_error.py

  • I delete all the text then add the first failing test to test_attribute_error.py

    1def test_failure():
2    assert False is True

  • I go back to the terminal to make a requirements file for the Python packages I need

    echo "pytest" > requirements.txt

    the terminal goes back to the command line.

  • I add pytest-watcher to the requirements file

    echo "pytest-watcher" >> requirements.txt

    the terminal goes back to the command line.

  • I use uv to install pytest-watcher with the requirements file

    uv add --requirement requirements.txt

    the terminal shows that it installed pytest-watcher and its dependencies.

  • I add the new files and folder to git for tracking

    git add .

    the terminal goes back to the command line.

  • I add a git commit message

    git commit -am 'setup project'

    the terminal shows a summary of the changes then goes back to the command line.

  • I use pytest-watcher to run the tests automatically

    uv run pytest-watcher . --now

    the terminal is my friend, and shows AssertionError

    ======================== FAILURES ========================
______________________ test_failure ______________________

    def test_failure():
>       assert False is True
E       assert False is True

test_attribute_error.py:2: AssertionError
================ short test summary info =================
FAILED test_attribute_error.py::test_failure - assert False is True
=================== 1 failed in X.YZs ====================

    because False is NOT True.

    if the terminal does not show the same error, then check if

    • your tests/__init__.py has two underscores (__) before and after init for __init__.py not _init_.py

    • you ran echo "pytest-watcher" >> requirements.txt, to add pytest-watcher to the requirements file

    and try uv run pytest-watcher . --now again

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

    1def test_failure():
2    assert False is True
3
4
5# Exceptions seen
6# AssertionError

  • I change True to False in the assertion

    1def test_failure():
2    # assert False is True
3    assert False is False
4
5
6# Exceptions seen
7# AssertionError

    the test passes.

  • I add an import statement at the top of test_attribute_error.py

    1import src.attribute_error

    the terminal is my friend, and shows ModuleNotFoundError

    ModuleNotFoundError: No module named 'src'

    because Python cannot find anything named src in this project.

  • I add ModuleNotFoundError to the list of Exceptions seen

     9# Exceptions seen
10# AssertionError
11# ModuleNotFoundError

  • I open a new terminal then change directories to attribute_error

    cd attribute_error

  • I use mkdir to make a folder named src in the project

    mkdir src

  • I go back to the terminal where the tests are running

  • I go to test_attribute_error.py and use ctrl/command+s on the keyboard to run the test again. The terminal shows ModuleNotFoundError

    ModuleNotFoundError: No module named 'src.attribute_error'

    because there is nothing named attribute_error in the src folder

  • I go to the second terminal

  • I use touch to make attribute_error.py in the src folder

    touch src/attribute_error.py

  • I go to the terminal where the tests are running and it shows the test is green again.

test_attribute_error_w_variables

AttributeError happens when I use a variable that does not exist in an object.

RED: make it fail

  • I change test_failure to test_attribute_error_w_variables

    1import src.attribute_error
2
3
4def test_attribute_error_w_variables():
5    src.attribute_error.variable_00
6
7
8# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'variable_00'

    because when src.attribute.variable_00 runs, Python follows this path

    src
└── attribute_error.py
    └── variable_00 # does not exist in attribute_error.py

    which raises AttributeError since there is nothing named variable_00 in attribute_error.py in the src folder, it is empty.

  • I add AttributeError to the list of Exceptions seen, in test_attribute_error.py

     8# Exceptions seen
 9# AssertionError
10# ModuleNotFoundError
11# AttributeError

GREEN: make it pass

  • I open attribute_error/__init__.py from the src folder

  • I add variable_00 to attribute_error.py

    1variable_00

    the terminal is my friend, and shows NameError

    NameError: name 'variable_00' is not defined

    because I used a name that is not defined in this file

  • I add NameError to the list of Exceptions seen, in test_attribute_error.py

     8# Exceptions seen
 9# AssertionError
10# ModuleNotFoundError
11# AttributeError
12# NameError

  • I point variable_00 to None to define it, in attribute_error.py

    1# variable_00
2variable_00 = None

    the test passes because

    • Python brings in an object for the attribute_error.py file from the src folder so I can use it in test_attribute_error.py as src.attribute_error when import src.attribute_error runs.

    • Python looks at what the variable_00 variable from the object it imported for the attribute_error.py file from the src folder (src.attribute_error) points to when src.attribute_error.variable_00 runs.

    I think of src.attribute_error.variable_00 like an address

    src.attribute_error.variable_00
src
└── attribute_error.py
    └── variable_00 = None

    • variable_00 is something in attribute_error, in this case it is a variable in attribute_error

    • attribute_error is something in src, in this case it is attribute_error.py (a module) in the src folder

    • src is something Python can import (a module, Python package or folder)

    • variable_00 is now an attribute/property of attribute_error.py in the src folder. I can use it from outside the file with src.attribute_error.variable_00

REFACTOR: make it better

  • I add a statement for variable_01 to test_attribute_error.py

    4def test_attribute_error_w_variables():
5    src.attribute_error.variable_00
6    src.attribute_error.variable_01
7
8
9# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'variable_01'.
                Did you mean: 'variable_00'?

  • I add variable_01 to attribute_error.py

    1# variable_00
2variable_00 = None
3variable_01

    the terminal is my friend, and shows NameError

    NameError: name 'variable_01' is not defined

  • I point it to None to define it

    1# variable_00
2variable_00 = None
3# variable_01
4variable_01 = variable_00

    the test passes because variable_01 is now an attribute of attribute_error.py in the src folder, and I can use it from outside the file with src.attribute_error.variable_01

    src.attribute_error.variable_01
src
└── attribute_error.py
    └── variable_01 = variable_00

  • I add a statement for variable_02 to test_attribute_error.py

     4def test_attribute_error_w_variables():
 5    src.attribute_error.variable_00
 6    src.attribute_error.variable_01
 7    src.attribute_error.variable_02
 8
 9
10# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'variable_02'.
                Did you mean: 'variable_00'?

  • I add variable_02 and point it to None in attribute_error.py

    1# variable_00
2variable_00 = None
3# variable_01
4variable_01 = variable_00
5variable_02 = variable_01

    the test passes because variable_02 is now an attribute of attribute_error.py in the src folder, and I can use it from outside the file with src.attribute_error.variable_02

    src.attribute_error.variable_02
src
└── attribute_error.py
    └── variable_02 = variable_01

  • I add a line for variable_03 to test_attribute_error.py

     4def test_attribute_error_w_variables():
 5    src.attribute_error.variable_00
 6    src.attribute_error.variable_01
 7    src.attribute_error.variable_02
 8    src.attribute_error.variable_03
 9
10
11# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'variable_03'.
                Did you mean: 'variable_00'?

  • I add variable_03 to attribute_error.py

    1# variable_00
2variable_00 = None
3# variable_01
4variable_01 = variable_00
5variable_02 = variable_01
6variable_03 = variable_02

    the test passes because variable_03 is now an attribute of attribute_error.py in the src folder, and I can use it from outside the file with src.attribute_error.variable_03

    src.attribute_error.variable_03
src
└── attribute_error.py
    └── variable_03 = variable_02

  • I add a line for variable_04 to test_attribute_error.py

     4def test_attribute_error_w_variables():
 5    src.attribute_error.variable_00
 6    src.attribute_error.variable_01
 7    src.attribute_error.variable_02
 8    src.attribute_error.variable_03
 9    src.attribute_error.variable_04
10
11
12# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'variable_04'.
                Did you mean: 'variable_00'?

  • I add variable_04 to attribute_error.py

    1# variable_00
2variable_00 = None
3# variable_01
4variable_01 = variable_00
5variable_02 = variable_01
6variable_03 = variable_02
7variable_04 = variable_03

    the test passes because variable_04 is now an attribute of attribute_error.py in the src folder, and I can use it from outside the file with src.attribute_error.variable_04

    src.attribute_error.variable_04
src
└── attribute_error.py
    └── variable_04 = variable_03

  • I add a line for variable_05 to test_attribute_error.py

     4def test_attribute_error_w_variables():
 5    src.attribute_error.variable_00
 6    src.attribute_error.variable_01
 7    src.attribute_error.variable_02
 8    src.attribute_error.variable_03
 9    src.attribute_error.variable_04
10    src.attribute_error.variable_05
11
12
13# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'variable_05'.
                Did you mean: 'variable_00'?

  • I add variable_05 to attribute_error.py

    1# variable_00
2variable_00 = None
3# variable_01
4variable_01 = variable_00
5variable_02 = variable_01
6variable_03 = variable_02
7variable_04 = variable_03
8variable_05 = variable_04

    the test passes because variable_05 is now an attribute of attribute_error.py in the src folder, and I can use it from outside the file with src.attribute_error.variable_05

    src.attribute_error.variable_05
src
└── attribute_error.py
    └── variable_05 = variable_04

  • I add a line for variable_06 to test_attribute_error.py

     4def test_attribute_error_w_variables():
 5    src.attribute_error.variable_00
 6    src.attribute_error.variable_01
 7    src.attribute_error.variable_02
 8    src.attribute_error.variable_03
 9    src.attribute_error.variable_04
10    src.attribute_error.variable_05
11    src.attribute_error.variable_06
12
13
14# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'variable_06'.
                Did you mean: 'variable_00'?

  • I add variable_06 to attribute_error.py

    1# variable_00
2variable_00 = None
3# variable_01
4variable_01 = variable_00
5variable_02 = variable_01
6variable_03 = variable_02
7variable_04 = variable_03
8variable_05 = variable_04
9variable_06 = variable_05

    the test passes because variable_06 is now an attribute of attribute_error.py in the src folder, and I can use it from outside the file with src.attribute_error.variable_06

    src.attribute_error.variable_06
src
└── attribute_error.py
    └── variable_06 = variable_05

  • I add a line for variable_07 to test_attribute_error.py

     4def test_attribute_error_w_variables():
 5    src.attribute_error.variable_00
 6    src.attribute_error.variable_01
 7    src.attribute_error.variable_02
 8    src.attribute_error.variable_03
 9    src.attribute_error.variable_04
10    src.attribute_error.variable_05
11    src.attribute_error.variable_06
12    src.attribute_error.variable_07
13
14
15# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'variable_07'.
                Did you mean: 'variable_00'?

  • I add variable_07 to attribute_error.py

     1# variable_00
 2variable_00 = None
 3# variable_01
 4variable_01 = variable_00
 5variable_02 = variable_01
 6variable_03 = variable_02
 7variable_04 = variable_03
 8variable_05 = variable_04
 9variable_06 = variable_05
10variable_07 = variable_06

    the test passes because variable_07 is now an attribute of attribute_error.py in the src folder, and I can use it from outside the file with src.attribute_error.variable_07

    src.attribute_error.variable_07
src
└── attribute_error.py
    └── variable_07 = variable_06

  • I add a line for variable_08 to test_attribute_error.py

     4def test_attribute_error_w_variables():
 5    src.attribute_error.variable_00
 6    src.attribute_error.variable_01
 7    src.attribute_error.variable_02
 8    src.attribute_error.variable_03
 9    src.attribute_error.variable_04
10    src.attribute_error.variable_05
11    src.attribute_error.variable_06
12    src.attribute_error.variable_07
13    src.attribute_error.variable_08
14
15
16# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'variable_08'.
                Did you mean: 'variable_00'?

  • I add variable_08 to attribute_error.py

     1# variable_00
 2variable_00 = None
 3# variable_01
 4variable_01 = variable_00
 5variable_02 = variable_01
 6variable_03 = variable_02
 7variable_04 = variable_03
 8variable_05 = variable_04
 9variable_06 = variable_05
10variable_07 = variable_06
11variable_08 = variable_07

    the test passes because variable_08 is now an attribute of attribute_error.py in the src folder, and I can use it from outside the file with src.attribute_error.variable_08

    src.attribute_error.variable_08
src
└── attribute_error.py
    └── variable_08 = variable_07

  • I add a line for variable_09 to test_attribute_error.py

     4def test_attribute_error_w_variables():
 5    src.attribute_error.variable_00
 6    src.attribute_error.variable_01
 7    src.attribute_error.variable_02
 8    src.attribute_error.variable_03
 9    src.attribute_error.variable_04
10    src.attribute_error.variable_05
11    src.attribute_error.variable_06
12    src.attribute_error.variable_07
13    src.attribute_error.variable_08
14    src.attribute_error.variable_09
15
16
17# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'variable_09'.
                Did you mean: 'variable_00'?

  • I add variable_09 to attribute_error.py

     1# variable_00
 2variable_00 = None
 3# variable_01
 4variable_01 = variable_00
 5variable_02 = variable_01
 6variable_03 = variable_02
 7variable_04 = variable_03
 8variable_05 = variable_04
 9variable_06 = variable_05
10variable_07 = variable_06
11variable_08 = variable_07
12variable_09 = variable_08

    the test passes because variable_09 is now an attribute of attribute_error.py in the src folder, and I can use it from outside the file with src.attribute_error.variable_09

    src.attribute_error.variable_09
src
└── attribute_error.py
    └── variable_09 = variable_08

  • I remove the commented lines

     1variable_00 = None
 2variable_01 = variable_00
 3variable_02 = variable_01
 4variable_03 = variable_02
 5variable_04 = variable_03
 6variable_05 = variable_04
 7variable_06 = variable_05
 8variable_07 = variable_06
 9variable_08 = variable_07
10variable_09 = variable_08

  • I add a git commit message in the other terminal

    git commit -am \
'add test_attribute_error_w_variables'

A variable in a module is an attribute of the module.

test_attribute_error_w_functions

RED: make it fail

  • I go back to the terminal where the tests are running

  • I add a test with a function call, to test_attribute_error.py

    14    src.attribute_error.variable_09
15
16
17def test_attribute_error_w_functions():
18    src.attribute_error.function_00()
19
20
21# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'function_00'

    because there is nothing named function_00 in attribute_error.py in the src folder.

GREEN: make it pass

  • I add the name and point it to None in attribute_error.py

    10variable_09 = variable_08
11
12
13function_00 = variable_09

    the terminal is my friend, and shows TypeError

    TypeError: 'NoneType' object is not callable

    because I cannot call None like a function.

  • I add TypeError to the list of Exceptions seen, in test_attribute_error.py

    21# Exceptions seen
22# AssertionError
23# ModuleNotFoundError
24# AttributeError
25# NameError
26# TypeError

  • I change the variable to a function in attribute_error.py

    10variable_09 = variable_08
11
12
13# function_00 = variable_09
14def function_00(): return variable_09

    the test passes because function_00 is now an attribute of attribute_error.py in the src folder, and I can call it from outside the file with src.attribute_error.function_00()

    src.attribute_error.function_00()
src
└── attribute_error.py
    └── def function_00(): return variable_09

REFACTOR: make it better

  • I remove the commented line

    1variable_09 = variable_08
2
3
4def function_00(): return variable_09

    time to make it a drill.

  • I add a call to function_01 from test_attribute_error_w_functions in test_attribute_error.py

    17def test_attribute_error_w_functions():
18    src.attribute_error.function_00()
19    src.attribute_error.function_01()
20
21
22# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'function_01'.
                Did you mean: 'function_00'?

  • I add a definition for function_01 to attribute_error.py

    13def function_00(): return variable_09
14def function_01(): return function_00()

    the test passes because function_01 is now an attribute of attribute_error.py in the src folder, and I can call it from outside the file with src.attribute_error.function_01()

    src.attribute_error.function_01()
src
└── attribute_error.py
    └── def function_01(): return function_00()

  • I add a call to function_02 from test_attribute_error_w_functions in test_attribute_error.py

    17def test_attribute_error_w_functions():
18    src.attribute_error.function_00()
19    src.attribute_error.function_01()
20    src.attribute_error.function_02()
21
22
23# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'function_02'.
                Did you mean: 'function_00'?

  • I add a definition for function_02 to attribute_error.py

    13def function_00(): return variable_09
14def function_01(): return function_00()
15def function_02(): return function_01()

    the test passes because function_02 is now an attribute of attribute_error.py in the src folder, and I can call it from outside the file with src.attribute_error.function_02()

    src.attribute_error.function_02()
src
└── attribute_error.py
    └── def function_02(): return function_01()

  • I add a call to function_03 from test_attribute_error_w_functions in test_attribute_error.py

    17def test_attribute_error_w_functions():
18    src.attribute_error.function_00()
19    src.attribute_error.function_01()
20    src.attribute_error.function_02()
21    src.attribute_error.function_03()
22
23
24# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'function_03'.
                Did you mean: 'function_00'?

  • I add a definition for function_03 to attribute_error.py

    13def function_00(): return variable_09
14def function_01(): return function_00()
15def function_02(): return function_01()
16def function_03(): return function_02()

    the test passes because function_03 is now an attribute of attribute_error.py in the src folder, and I can call it from outside the file with src.attribute_error.function_03()

    src.attribute_error.function_03()
src
└── attribute_error.py
    └── def function_03(): return function_02()

  • I add a call to function_04 from test_attribute_error_w_functions in test_attribute_error.py

    17def test_attribute_error_w_functions():
18    src.attribute_error.function_00()
19    src.attribute_error.function_01()
20    src.attribute_error.function_02()
21    src.attribute_error.function_03()
22    src.attribute_error.function_04()
23
24
25# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'function_04'.
                Did you mean: 'function_00'?

  • I add a definition for function_04 to attribute_error.py

    13def function_00(): return variable_09
14def function_01(): return function_00()
15def function_02(): return function_01()
16def function_03(): return function_02()
17def function_04(): return function_03()

    the test passes because function_04 is now an attribute of attribute_error.py in the src folder, and I can call it from outside the file with src.attribute_error.function_04()

    src.attribute_error.function_04()
src
└── attribute_error.py
    └── def function_04(): return function_03()

  • I add a call to function_05 from test_attribute_error_w_functions in test_attribute_error.py

    17def test_attribute_error_w_functions():
18    src.attribute_error.function_00()
19    src.attribute_error.function_01()
20    src.attribute_error.function_02()
21    src.attribute_error.function_03()
22    src.attribute_error.function_04()
23    src.attribute_error.function_05()
24
25
26# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'function_05'.
                Did you mean: 'function_00'?

  • I add a definition for function_05 to attribute_error.py

    13def function_00(): return variable_09
14def function_01(): return function_00()
15def function_02(): return function_01()
16def function_03(): return function_02()
17def function_04(): return function_03()
18def function_05(): return function_04()

    the test passes because function_05 is now an attribute of attribute_error.py in the src folder, and I can call it from outside the file with src.attribute_error.function_05()

    src.attribute_error.function_05()
src
└── attribute_error.py
    └── def function_05(): return function_04()

  • I add a call to function_06 from test_attribute_error_w_functions in test_attribute_error.py

    17def test_attribute_error_w_functions():
18    src.attribute_error.function_00()
19    src.attribute_error.function_01()
20    src.attribute_error.function_02()
21    src.attribute_error.function_03()
22    src.attribute_error.function_04()
23    src.attribute_error.function_05()
24    src.attribute_error.function_06()
25
26
27# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'function_06'.
                Did you mean: 'function_00'?

  • I add a definition for function_06 to attribute_error.py

    13def function_00(): return variable_09
14def function_01(): return function_00()
15def function_02(): return function_01()
16def function_03(): return function_02()
17def function_04(): return function_03()
18def function_05(): return function_04()
19def function_06(): return function_05()

    the test passes because function_06 is now an attribute of attribute_error.py in the src folder, and I can call it from outside the file with src.attribute_error.function_06()

    src.attribute_error.function_06()
src
└── attribute_error.py
    └── def function_06(): return function_05()

  • I add a call to function_07 from test_attribute_error_w_functions in test_attribute_error.py

    17def test_attribute_error_w_functions():
18    src.attribute_error.function_00()
19    src.attribute_error.function_01()
20    src.attribute_error.function_02()
21    src.attribute_error.function_03()
22    src.attribute_error.function_04()
23    src.attribute_error.function_05()
24    src.attribute_error.function_06()
25    src.attribute_error.function_07()
26
27
28# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'function_07'.
                Did you mean: 'function_00'?

  • I add a definition for function_07 to attribute_error.py

    13def function_00(): return variable_09
14def function_01(): return function_00()
15def function_02(): return function_01()
16def function_03(): return function_02()
17def function_04(): return function_03()
18def function_05(): return function_04()
19def function_06(): return function_05()
20def function_07(): return function_06()

    the test passes because function_07 is now an attribute of attribute_error.py in the src folder, and I can call it from outside the file with src.attribute_error.function_07()

    src.attribute_error.function_07()
src
└── attribute_error.py
    └── def function_07(): return function_06()

  • I add a call to function_08 from test_attribute_error_w_functions in test_attribute_error.py

    17def test_attribute_error_w_functions():
18    src.attribute_error.function_00()
19    src.attribute_error.function_01()
20    src.attribute_error.function_02()
21    src.attribute_error.function_03()
22    src.attribute_error.function_04()
23    src.attribute_error.function_05()
24    src.attribute_error.function_06()
25    src.attribute_error.function_07()
26    src.attribute_error.function_08()
27
28
29# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'function_08'.
                Did you mean: 'function_00'?

  • I add a definition for function_08 to attribute_error.py

    13def function_00(): return variable_09
14def function_01(): return function_00()
15def function_02(): return function_01()
16def function_03(): return function_02()
17def function_04(): return function_03()
18def function_05(): return function_04()
19def function_06(): return function_05()
20def function_07(): return function_06()
21def function_08(): return function_07()

    the test passes because function_08 is now an attribute of attribute_error.py in the src folder, and I can call it from outside the file with src.attribute_error.function_08()

    src.attribute_error.function_08()
src
└── attribute_error.py
    └── def function_08(): return function_07()

  • I add a call to function_09 from test_attribute_error_w_functions in test_attribute_error.py

    17def test_attribute_error_w_functions():
18    src.attribute_error.function_00()
19    src.attribute_error.function_01()
20    src.attribute_error.function_02()
21    src.attribute_error.function_03()
22    src.attribute_error.function_04()
23    src.attribute_error.function_05()
24    src.attribute_error.function_06()
25    src.attribute_error.function_07()
26    src.attribute_error.function_08()
27    src.attribute_error.function_09()
28
29
30# Exceptions seen

    the terminal is my friend, and shows AttributeError

    AttributeError: module 'src.attribute_error'
                has no attribute 'function_09'.
                Did you mean: 'function_00'?

  • I add a definition for function_09 to attribute_error.py

    13def function_00(): return variable_09
14def function_01(): return function_00()
15def function_02(): return function_01()
16def function_03(): return function_02()
17def function_04(): return function_03()
18def function_05(): return function_04()
19def function_06(): return function_05()
20def function_07(): return function_06()
21def function_08(): return function_07()
22def function_09(): return function_08()

    the test passes because function_09 is now an attribute of attribute_error.py in the src folder, and I can call it from outside the file with src.attribute_error.function_09()

    src.attribute_error.function_09()
src
└── attribute_error.py
    └── def function_09(): return function_08()

  • I add a git commit message in the other terminal

    git commit -am \
'add test_attribute_error_w_functions'

A function in a module is an attribute of the module

close the project

  • I close attribute_error.py and test_attribute_error.py

  • I click in the terminal where the tests are running

  • I use q on the keyboard to leave the tests. The terminal goes back to the command line.

  • I change directory to the parent of attribute_error

    cd ..

    the terminal shows

    .../pumping_python

    I am back in the pumping_python directory.

review

I ran tests for AttributeError that showed

I also saw these Exceptions

My problem with the tests is that they all show the correct way to use attributes I made in attribute_error.py. If someone reads the file or runs it, there is no way for them to know how the code relates to AttributeError unless they go through the process with me, there has to be a better way.

code from the chapter

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

what is next?

Would you like to see me separate the tests and functions in the type_error project?

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