CONTRIBUTING.md

How to contribute

Thank you for your interest in the trackintel development. All contributions, bug reports, bug fixes, documentation improvements, enhancements, and ideas are welcome.

Development

You can download the whole repository and install trackintel locally using pip install .. For quick testing, use trackintel.print_version().

Testing is done using pytest. Simply run the tests using pytest in the top-level trackintel folder. In case you use pipenv, install pytest first (pip install pytest), then run pytest using this version: python -m pytest. The use of fixtures for data generation (e.g., trips and trackpoints) is still an open todo. As for now, there are some smaller datasets in the tests folder.

Documentation

The documentation follws the pandas resp. numpy docstring standard. In particular, it uses Sphinx to create the documentation. You can install Sphinx using pip install -U sphinx or conda install sphinx.

If you use additional dependencies during development, do not forget to add them to autodoc_mock_imports in docs/conf.py for readthedocs.org to work properly.

You can then generate the documentation using sphinx-build -b html docs docs.gen. This will put the documentation in docs.gen, which is in .gitignore.

Continuous Integration

There are travis and appveyor CIs set up for Unix/Windows builds. You can find the corresponding scripts in .travis.yml and appveyor.yml. Adding Coveralls is an open todo.

Formatting

We use black as our code formatter, run python -m black . -l 120 in the trackintel folder to format your code automatically into black style. We additionally use Flake8 checker. Please be sure to format your code before making a pull request. If you wish, you can add pre-commit hooks for both flake8 and black to make all formatting easier.

Coding conventions

This is a place to collect conventions we agreed upon until we find the right place in the doc for them

Time stamps

All timestamps are timezone aware pandas datetime64[ns, UTC] objects. The default timezone should be UTC but the user should be free to use a different one if he wants. See Issue 101.

Tests

Organization of tests

See Issue 23

• The test folder copies the folder structure that the trackintel.trackintel folder has.
• Every python module has a single test file
• Every function has 1 test class
• Every method of this function should test a single property

Test data

If possible test data should be

• independent of unrelated preprocessing steps (e.g., avoid starting with positionfixes if you write tests for trips)
• simple and easy to understand (e.g., try to have a short example with an isolated special case rather than a large dataset that contains a lot of special cases)
• defined directly in the code itself (e.g, this example

Integrety of input data

Functions should never change the input dataframe but rather return an altered copy.

Adressing geometry columns

Geometry columns should never be adressed by name but by the geometry attribute Issue 14, Issue 15

Order of functions in code

The main function should be on the top of the file, the internal/secondary functions should be at the end of the file

ID management

All trackintel objects have an ID that is the index of the dataframe Issue 97

Docstrings

See issue 117

• All docstrings follow the numpy format.
• The example section is mandatory.

Performance benchmarking

• We use airspeed velocity to benchmark key trackintel functions.
• Benchmarks are written in the airspeed velocity format.
• Three types of benchmarks exist (sample at benchmarks folder))

  • mem which measures the memory of the data structure returned: https://github.com/mie-lab/trackintel/blob/19fcf965fce4a2bca2032f72b2759c7625c02b2f/benchmarks/preprocessing_benchmarks.py#L24

  • peakmem which measure the peak memory usage: https://github.com/mie-lab/trackintel/blob/19fcf965fce4a2bca2032f72b2759c7625c02b2f/benchmarks/preprocessing_benchmarks.py#L27

  • time which measure run time: https://github.com/mie-lab/trackintel/blob/19fcf965fce4a2bca2032f72b2759c7625c02b2f/benchmarks/preprocessing_benchmarks.py#L21

• We store the benchmark html files in the gh-pages branch for hosting them on the server. Detailed instructions for re-running existing benchmarks can be found in the ASV-BENCHMARKS.MD file here.

Others

• We limit all lines to a maximum of 120 characters.
• New release version tags use semantic numbering.
• Commits follow the standard of pandas.
• There should be no warnings when running tests.
• We agreed on the following naming conventions for trackintel datatypes:
  • long: positionfixes, staypoints, triplegs, locations, trips, and tours
  • short: pfs, sp, tpls, locs, trips, tours

Version release checklist

Before you release a new version you should check/modify the following files:

• trackintel/__ version__.py -> update the version number

• docs/conf.py -> update the version number

• check setup.py if new dependencies need greater python version

After the release is tagged, no new release with the same version number can be published on pypi!