python-improvers-2

Python Improvers course. This is a new course based on lessons learned from the pre-pandemic Python Improvers course found at https://github.com/BritishGeologicalSurvey/python-improvers

The aim is to teach how to write Python scripts in a modular, reusable fashion using readable Pythonic code.

Local setup instructions

Ensure that the following software is installed on your machine:

• conda or similar package manager (e.g. Anaconda/Miniconda)
• VS Code
• Git (optional)

Download the project repository, either via git clone or with "Download ZIP" within the "Code" menu.

Open a terminal window that has access to the conda command. On Windows, this may be by choosing the CMD.exe prompt from the Anaconda Navigator.

Create the virtual environment.

conda env create -f environment.yml

If you are not on a Windows system, or have problems installing the packages, try using environment_unversioned.yml instead. This doesn't have pinned versions, which will allow the solver to choose appropriate versions for your system.

IDEs

This course is aimed at VS Code, but can also be done with a combination of Spyder and Jupyter. With appropriate extensions, VS Code can replicate the behaviour of both Spyder and Jupyter, but with better syntax highlighting and a built-in terminal.

The following VS Code extensions are recommended:

• Python (Microsoft)
• Pylance (Microsoft)
• Jupyter (Microsoft)
• Data Wrangler (Microsoft)
• Flake8 (Microsoft)
• Black Formatter (Microsoft)
• RainbowCSV (Mechatroner)
• Vim (vscodevim) - only if you like Vim key bindings

Using VS Code more like Spyder.

• Open Python file
• At top right, press "Run Current File in Interactive Window".
• Interactive window has Jupyter Variables button

To be able to execute code in the interactive terminal with ctrl + enter, do the following:

• Preferences: Open User Settings
• Search for "Jupyter execute selection"
• Select the checkbox on "Jupyter > Interactive Window > Text Editor: Execute Selection". This added "jupyter.interactiveWindow.textEditor.executeSelection": true to the settings.json.

Linting

The following command-line linting tools are recommended. These are provided in the environment specification.

flake8 test.py  # General code layout, redundant code and syntax errors
pylint test.py  # Code style
mypy test.py  # Static type checking

Lessons

The lessons are provided as IPython notebooks in the lessons folder. As well as the main lessons, topics that have been covered in Python clinics can also be included. Some of these are:

• Dates and times with datetime
• Text parsing and regular expressions
• Testing code with pytest
• Geopandas for spatial data analysis
• Running external commands with subprocess
• Interactive debugging with breakpoint and pdb