Introduction

The following document should describe a default Python development environment. Which I created in relation to my needs, while working with Python. Feel free to suggest improvements and tips!

Tested and written for Windows 10

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Components

Package Manager

Anaconda (https://www.anaconda.com)

Editor

Visual Studio Code (https://code.visualstudio.com)

Linting check

flake8 (https://flake8.pycqa.org/en/latest)

Pre commit checks

pre-commit (https://pre-commit.com)

How to install and prepare it?

Package manager

• Download the anaconda installer from the website (Python 3.x and / or python 2.x)
• Run the installer and select all defaults (optional PATH)

Editor

• Download the vsc installer from the website
• Run the installer and select all defaults (optional PATH)

Reboot your computer

Init Conda

Open cmd or PowerShell and run:

conda init

Prepare VSC

• Press Shift + Ctrl + P and type Terminal: Select Default Shell
• Now select as Terminal Command Promt

Linting Check

Install flake8 via conda

conda activate
conda install -c conda-forge flake8
pip install hacking pylint

Add to VSC the module cornflakes-linter

• Switch with Ctrl+Shift+X to the extension widnows, search for the module cornflakes-linter and press install.
• Open cmd and type where flake8 to locate the executable and copy the path.
• Use Ctrl+, to open the settings and search for executablePath and paste the path from the previous command.
• Now linting with flake8 should be active, you can test it by open a py file and save it after writing some code.
• The output is shown in the PROBLEMS console and in the python code.

Configure flake8

You can configure flake8 per project through the file tox.ini, which should be in the root folder. This config will also effects parts of the flake8 pre-commit hook (exclude, ignore e.g.)! A basic config can be found in teh file files/examples/tox.ini

The main focus should be on ignore and exclude which offer the possibility to ignore error codes and exclude files from the check. But you can set also many other values, for more check out https://flake8.pycqa.org/en/latest/user/options.html#options-list

The error code of flake8 are E***, W*** used in pep8 and F*** and C9**.

E***/W***: Error and warning of pep8
F***: Detection of PyFlakes
C9**: Detection of circulate complexity by McCabe

Error codes overview: https://flake8.pycqa.org/en/latest/user/error-codes.html

Pre commit check

Install it from anaconda

conda activate
conda install -c conda-forge pre-commit

(alternatively) Install it with pip

conda activate
pip install pre-commit

How to use it?

Checks

[ ? ] Is anaconda already installed?  
[ ? ] Is the correct anaconda version installed?  
[ ? ] Are all steps freom the previous part done?  

When to create a new environment?

[ Y ] Do you start a new project?  
[ N ] Do you need a new environment in a project? 

Steps

create / checkout a git repo

Create a new git repo

git init
git add FILES
git commit -m "MSG"
git remote add origin https://github.com/example/repo.git
git push -u origin master

Or add an existing one (be aware that there can be problems!)

git clone https://github.com/example/repo.git

.gitignore

Create a .gitignore file, update yours or use the one from the example folder.

files/examples/.gitignore

VS Code Workspace

In a Workspace can settings be definded, among others. These override user settings. Workspace settings are specific to a project and can be shared across developers on a project. You find more on https://code.visualstudio.com/docs/getstarted/settings

Create a new workspace

Open VS Code and open the folder you created with File -> Open Folder.... or press Ctrl + K Ctrl + O Alternativly you can right click in the checkout folder and select Open with code. Save teh Workspace in the folder with File -> Save workspace As...

Setup environment

Create new Python environment

Creating a seperate python environment for every project or even for stages is very usefull. To do this follow these steps.

• open Anaconda Navigator or Anaconda prompt

  • switch to Environments and click Create at the bottom
  • Enter the name and select the Python version and create it

• Select the environment in your VSC

  • Press Shift + Ctrl + P and type Python: Select Interpreter
  • Now select the python env you want to us

Configure the environment

Adding modules to your environment

Search them in the Anaconda Cloud (https://anaconda.org, maybe you need to add a channel)

Use the gui to install them (the complicate way 😉 )

• Open the anaconda navigator and switch to Environments
• Change the Environment for that you want to install the package and in the drop down from installed to All
• Put into Search Packages the name of the package and click the checkbox
• After you selected all packages, click Apply to install them and a second time to confirm the overall change

Use the cli to install them (the easy way 😉 )

• Open the anaconda prompt or the cmd
• Activate your environment with conda activate ENV_NAME
• Type conda install -c CHANNEL PACKAGE to install the package

conda activate
conda install -c conda-forge pytesseract

Configure pre-commit

To install and configure pre-commit, create / add the pre-commit configuration file .pre-commit-config.yaml to your project root. Decide what you need from the pre commit hooks and remove if unneccessary ( these checks could slow down commits). Finally, install the pre-commit hooks with pre-commit install. These checks are executed when you enter git commit -m "comment". At the first execution, all hooks are downloaded and prepared, so it takes some time.

Using the linting / flake8

Flake8 is integrated as linting checker and enhanced by the installed module cornflakes-linter.

Ignore a error code
Add them into the ``tox.ini`` behind ``ignore =`` and add a comment what and why this ignore.

Exclude files or directories
Add them into the ``tox.ini`` behind ``exclude =`` and add a comment what and why this ignore.

Working with pre-commit

Pre-commit checks your code by upfront defined criteria before the commit is created. Don't exclude checks or remove them, except there is good reason, these checks are usefull for the overall code quality! Checks that would modifie a file will allways fail the commit. You need to adopt these changes, add the file and run commit again.

How to stay up2date?

Package Manager

Anaconda Navigator checks on the startup if an update is available and ask you if you want to update

Packages

The packages can be easily updated with the following commands. All envs

conda update --all  

Spezific envs

conda update -n ENV --all

Editor

Visual Studio Code has an automatic update function, alternatively you can open "Help -> Check for Updates"

Pre-Commit

You can update your hooks to the latest version automatically by running pre-commit autoupdate. By default, this will bring the hooks to the latest tag on the master branch.

FAQ / Know Error

Pre-Commit fails with files were modified by this hook

This works as designed. If a hook modifies files then the commit itself was not ready. You can inspect whether the modifications were correct, re-add, and commit as usual. Modifications are treated as "failure" and let the intelligent end user perform the correct actions.

conda activate throws error that your shell is not ready

You need to init conda the first time you run it.

conda init

Disable telemtry

If you don't wish to send usage data to Microsoft, you can set the telemetry.enableTelemetry user setting to false. VS Code lets you add features to the product by installing Microsoft and third-party extensions. These extensions may be collecting their own usage data and are not controlled by the telemetry.enableTelemetry setting.

File > Preferences > Settings, search for telemetry, and uncheck the Telemetry: Enable Telemetry

Source

Among other things, these where some sources whcih have been used.

VSC

https://code.visualstudio.com/docs
https://code.visualstudio.com/docs/getstarted/telemetry
https://code.visualstudio.com/docs/python/python-tutorial
https://code.visualstudio.com/docs/python/linting

Anaconda in VSC

https://code.visualstudio.com/docs/python/environments
https://code.visualstudio.com/docs/editor/integrated-terminal#_configuration

Anaconda

https://www.anaconda.com/keeping-anaconda-date/

pre-commit

https://pre-commit.com/
https://github.com/prettier/prettier

Linting

https://flake8.pycqa.org/en/latest/user/configuration.html