nycdb 0.2.6

database of nyc housing data

NYCDB

a tool for building a database of NYC housing data

This is a Python library and cli tool for installing, updating and managing NYCDB, a postgres database of NYC Housing Data.

For more background information on this project and links to download copies of full database dump visit: https://github.com/nycdb/nycdb. We use the term nycdb to refer to both the python software and the running copy of the postgres database.

Using the cli tool

You will need python 3.6+ and Postgres. The latest version can be installed from pypi with pip: python3 -m pip install nycdb

If the installation is successful, you can view a summary of the tool's options by running nycdb --help

To print a list of datasets: nycdb --list-datasets

nycdb's main job is to download datasets and import them into postgres. It does not manage the database for you. You can use the flags -U/--user, -D/--database, -P/--password, and -H/--host to instruct nycdb to connect to the correct database. See nycdb --help for the defaults.

Example: downloading, loading, and verifying the dataset hpd_violations:

nycdb --download hpd_violations
nycdb --load hpd_violations
nycdb --verify hpd_violations

You can also verify all datasets: nycdb --verify-all

By default the downloaded data files are is stored in ./data. Use --root-dir to change the location of the data directory.

You can export a .sql file for any dataset by using the --dump command

Development

There are two development workflows: one using python virtual environments and one using docker.

Using docker and docker-compose

To get started all you have to do is run docker-compose up.

On the first run Docker will take longer to downloads and build the images. It will start a Postgres server on port 5432 of your local machineYou can also press CTRL-C at any point to stop the server.

In a separate terminal, you will be able to now use the nycdb cli: docker-compose run nycdb --help

You can also open a python3 shell: docker-compose run --entrypoint=python3 nycdb or run the test suit docker-compose run --entrypoint="pytest tests" nycdb

You may also develop on nycdb itself:

• Any changes you make to the tool's source code will automatically be reflected in future invocations of nycdb and the test suite.
• The postgres database server is forwarded to localhost:5432 which you can connect to via a desktop client if you like.
• If you don't have a desktop Postgres client, you can always run nycdb --dbshell to interactively inspect the database with psql.

To update the database after adding new packages or dev dependencies, just run docker-compose up --build --force-recreate --no-deps. This command will take a bit longer than the regular docker-compose up command, but will reinstall packages within the docker container without removing any downloaded files or database data from the docker database.

To stop the database run docker-compose down. The downloaded files and database data are stored in docker volumes and are not automatically removed.

However, if you ever want to wipe the database, run docker-compose down -v.

Python3 virtual environments

If you have postgres installed separately, you can use this alternative method without docker:

Setup and active a virtual environment:

python3 -m venv venv
source venv/bin/activate

Install nycdb: pip install -e ./src

As long as the virtual environment is activated, you can use nycdb directly in your shell.

Adding New Datasets

See the guide here for the steps to add a new dataset