how to make a Python Test Driven Development environment automatically on Windows without Windows Subsystem for Linux


You made it this far and have become the greatest programmer in the world. To follow The Do Not Repeat Yourself (DRY) Principle, I write a program with the commands to make a Python Test Driven Development environment on a Windows Computer that does NOT have Windows Subsystem for Linux anytime I want so I do not have to remember every step of the process or do them manually.

To review, here are steps I take to make the environment for every project

  1. I pick a name for the project

  2. I make a directory for the project

  3. I change directory to the project

  4. I make a directory for the source code

  5. I make a Python file to hold the source code in the ‘src’ folder

  6. I make a directory for the tests

  7. I make the ‘tests’ folder a Python package

  8. I make a Python file to hold the tests in the ‘tests’ folder

  9. I add the first failing test to the test file

  10. I make a virtual environment

  11. I activate the virtual environment

  12. I upgrade the Python package manager

  13. I make a requirements file for the needed Python packages

  14. I install the packages listed in the requirements file

  15. I run the tests automatically

  16. I open the test file in the editor from the terminal

  17. I make the test pass

  18. then I start working on the project

I want to give one command for the program to do every step except

this way I only need to do 3 steps instead of 18

preview

Here is the program I have by the end of the chapter to automatically make a python test driven development environment, it is only 27 lines of code, with spaces

questions about making a Python Test Driven Development Environment automatically on Windows without Windows Subsystem for Linux

Here are questions you can answer after going through this chapter


how to make a PowerShell script

  • I go to the terminal and use New-Item to make an empty file with a name that is easy to remember later. I want the name to also describe the program that will automatically make a Test Driven Development environment for me

    New-Item makePythonTdd.ps1
    

    the terminal goes back to the command line

  • I open makePythonTdd.ps1 in the editor of the Integrated Development Environment (IDE), then add the commands I use to make a Python Test Driven Development environment for a project

     1mkdir magic_again
     2cd magic_again
     3mkdir src
     4New-Item src/magic_again.py
     5mkdir tests
     6New-Item tests/__init__.py
     7New-Item tests/test_magic_again.py
     8python -m venv .venv
     9.venv/scripts/activate.ps1
    10python -m pip install --upgrade pip
    11"pytest-watch" | Out-File requirements.txt -Encoding UTF8
    12python -m pip install --requirement requirements.txt
    13pytest-watch
    
  • test_magic_again.py is an empty file becuase I used New-Item. I want it to have the text for the first failure so I do not have to open the editor to add the text for it in each project. I use Out-File to add the text to test_magic_again.py when it makes the file in the tests folder, the same I do with the requirements.txt file

     5mkdir tests
     6New-Item tests/__init__.py
     7
     8"" | Out-File "tests/test_magic.py" -Encoding UTF8
     9
    10python -m venv .venv
    11.venv/scripts/activate.ps1
    
  • I add the text for the test inside the quotes (“”) I just added to makePythonTdd.sh, the way I do with Out-File when I add "pytest-watch" as text in requirements.txt

    Caution

    Indentation is important in Python, I use 4 spaces as convention in this book, see the Python Style Guide for more

     8"import unittest
     9
    10
    11class TestMagicAgain(unittest.TestCase):
    12
    13    def test_failure(self):
    14        self.assertFalse(True)
    15
    16
    17# Exceptions Encountered
    18# AssertionError
    19" | Out-File "tests/test_magic_again.py" -Encoding UTF8
    

how to run a PowerShell script

  • I go back to the terminal to run the program

    makePythonTdd.ps1
    

    the terminal shows

    command not found: makePythonTdd.ps1
    

    I have to tell the computer where the file is

    .\makePythonTdd.ps1
    

    .\ is shorthand for this directory which in this case is pumping_python where makePythonTdd.ps1 is saved. The terminal shows

    ======================================= FAILURES =======================================
    _____________________________ TestMagicAgain.test_failure _____________________________
    
    self = <tests.test_magic_again.TestMagicAgain testMethod=test_failure>
    
        def test_failure(self):
    >       self.assertFalse(True)
    E       AssertionError: True is not false
    
    tests/test_magic_again.py:7: AssertionError
    =============================== short test summary info ================================
    FAILED tests/test_magic_again.py::TestMagic::test_failure - AssertionError: True is not false
    ================================== 1 failed in X.YZs ===================================
    

    Success! I just made a program that can make the magic_again project anytime I want and it automatically does the steps I did manually.

  • I hold ctrl on the keyboard and click on tests/test_magic_again.py to open it in the editor then make the test pass

  • I hit ctrl+c in the terminal to stop the test

  • I deactivate the virtual environment

    deactivate
    

    the terminal goes back to the command line

  • I leave the magic folder to go back to the pumping_python folder

    cd ..
    

    the terminal shows

    ...\pumping_python >
    
  • I want to use makePythonTdd.ps1 to make another project with a different name. I change magic_again to the name of the new project in the editor

    Note

    The lines that are changing in the code are highlighted

     1mkdir more_magic
     2cd more_magic
     3mkdir src
     4touch src/more_magic.py
     5mkdir tests
     6touch tests/__init__.py
     7
     8"import unittest
     9
    10
    11class TestMoreMagic(unittest.TestCase):
    12
    13    def test_failure(self):
    14        self.assertFalse(True)
    15
    16
    17# Exceptions Encountered
    18# AssertionError
    19" | Out-File "tests/test_more_magic.py" - Encoding UTF8
    
  • I run makePythonTdd.ps1 in the terminal to make a project named more_magic

    ./makePythonTdd.ps1
    

    the terminal shows AssertionError

    ======================================= FAILURES =======================================
    _____________________________ TestMoreMagic.test_failure ______________________________
    
    self = <tests.test_more_magic.TestMoreMagic testMethod=test_failure>
    
        def test_failure(self):
    >       self.assertFalse(True)
    E       AssertionError: True is not false
    
    tests/test_more_magic.py:7: AssertionError
    =============================== short test summary info ================================
    FAILED tests/test_more_magic.py::TestMoreMagic::test_failure - AssertionError: True is not false
    ================================== 1 failed in X.YZs ===================================
    

    I make the test pass

  • I hit ctrl+c to exit the tests in the terminal

the program works and can make a Python Test Driven Development environment automatically the way I want every time


close the project

  • I close the test_more_magic.py in the editor I had open

  • I exit the tests in the terminal 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\more_magic
    
  • I change directory to the parent of more_magic

    cd ..
    

    the terminal shows

    ...\pumping_python
    

    I am back in the pumping_python directory


review

Computer Programming allows me to take some steps and make them a one line command for the computer to do for me. You have seen a way I can make a Python Test Driven Development environment, with a program to do it on any Windows computer without Windows Subsystem for Linux.

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


Click Here to see the code for the program to make a Python Test Driven Development environment for any Linux or MacOS computers


what is next?

Here is what we have gone through together so far

Would you like to use makePythonTdd.ps1 to make a Python Test Driven Development environment to test that an Exception is raised?


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