dataset: databases for lazy people

Although managing data in relational database has plenty of benefits, they’re rarely used in day-to-day work with small to medium scale datasets. But why is that? Why do we see an awful lot of data stored in static files in CSV or JSON format, even though they are hard to query and update incrementally?

The answer is that programmers are lazy, and thus they tend to prefer the easiest solution they find. And in Python, a database isn’t the simplest solution for storing a bunch of structured data. This is what dataset is going to change!

dataset provides two key functions that make using SQL databases in Python a breeze:

  • A simple abstraction layer removes most direct SQL statements without the necessity for a full ORM model - essentially, databases can be used like a JSON file or NoSQL store.
  • Database contents can be exported (frozen) using a sophisticated plain file generator with JSON and CSV support. Exports can be configured to include metadata and dynamic file names depending on the exported data. The exporter can also be used as a command-line tool, datafreeze.

A simple data loading script using dataset might look like this:

import dataset

db = dataset.connect('sqlite:///:memory:')

table = db['sometable']
table.insert(dict(name='John Doe', age=37))
table.insert(dict(name='Jane Doe', age=34, gender='female'))

john = table.find_one(name='John Doe')

Here is similar code, without dataset.

Features

  • Automatic schema: If a table or column is written that does not exist in the database, it will be created automatically.
  • Upserts: Records are either created or updated, depending on whether an existing version can be found.
  • Query helpers for simple queries such as all rows in a table or all distinct values across a set of columns.
  • Compatibility: Being built on top of SQLAlchemy, dataset works with all major databases, such as SQLite, PostgreSQL and MySQL.
  • Scripted exports: Data can be exported based on a scripted configuration, making the process easy and replicable.

Contributors

dataset is written and maintained by Friedrich Lindenberg, Gregor Aisch and Stefan Wehrmeyer. Its code is largely based on the preceding libraries sqlaload and datafreeze. And of course, we’re standing on the shoulders of giants.

Our cute little naked mole rat was drawn by Johannes Koch.

dataset

Because managing databases in Python should be as simple as reading and writing JSON files.

Overview

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