Using TinyDB

I just found this neat Python module called TinyDB. It’s a document based database that is written in pure Python with ~1800(!) lines of code, 40% of which I hear is comments(!!). And there’s full(!!!) test coverage? Which implies that they performed any kind of testing at all? Crazy stuff. In this post I’ll provide a small sample of inserting recipes and querying them.

Database Creation and Data Entry

The first part is pretty straight forward–we import the database, a function called where, and then we create a database called “tiny.db”, because we’re programmers, and unoriginal.

import tinydb
from tinydb import where
db = tinydb.TinyDB("tiny.db")

Next we create a list of dicts called recipes, and then insert them into our database.

recipes = [{"name":"Fried Rice", "ingredients":["rice","onion","garlic","carrot","egg","peas","soy sauce"]},
           {"name":"Thai Street Pancakes", "ingredients":["wheat","green onion","garlic","shrimp","onion","mushroom","crab","soy sauce","sesame oil","lemon juice"]}]

Find a Specific Value

This is easy thanks to the where() method imported separately at the top.

db.search( where("name") == "Fried Rice" )
[{u'ingredients': [u'rice',
   u'onion',
   u'garlic',
   u'carrot',
   u'egg',
   u'peas',
   u'soy sauce'],
  u'name': u'Fried Rice'}]

Find an Element in a List

Then we can search the value of the "ingredients" key using the .any method and this returns what we’d expect,

db.search( where("ingredients").any("onion") )
[{u'ingredients': [u'rice',
   u'onion',
   u'garlic',
   u'carrot',
   u'egg',
   u'peas',
   u'soy sauce'],
  u'name': u'Fried Rice'},
 {u'ingredients': [u'wheat',
   u'green onion',
   u'garlic',
   u'shrimp',
   u'onion',
   u'mushroom',
   u'crab',
   u'soy sauce',
   u'sesame oil',
   u'lemon juice'],
  u'name': u'Thai Street Pancakes'}]

There is also a .all() method that works similar to the built-in all() function in Python. More advanced usage, such as grabbing element ids, or searching with regex can be found on the Advanced Usage page.

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