Introducing Box – Python dictionaries with recursive dot notation access

Everyone loves Python’s dictionaries; they’re fast, easy to create and quite handy for a range of reasons. However, there are times that ["typing"]["out"]["all"]["those"] extra quotes and  brackets seems excessive. Wouldn’t it be nicer to access.them.like.class.methods?

Say hello to box.

from box import Box

movie_data = {
  "movies": {
    "Spaceballs": {
      "imdb_stars": 7.1,
      "rating": "PG",
      "length": 96,
      "Director": "Mel Brooks",
      "Stars": [{"name": "Mel Brooks", "imdb": "nm0000316", "role": "President Skroob"},
                {"name": "John Candy","imdb": "nm0001006", "role": "Barf"},
                {"name": "Rick Moranis", "imdb": "nm0001548", "role": "Dark Helmet"}
      ]
    },
    "Robin Hood: Men in Tights": {
      "imdb_stars": 6.7,
      "rating": "PG-13",
      "length": 104,
      "Director": "Mel Brooks",
      "Stars": [
                {"name": "Cary Elwes", "imdb": "nm0000144", "role": "Robin Hood"},
                {"name": "Richard Lewis", "imdb": "nm0507659", "role": "Prince John"},
                {"name": "Roger Rees", "imdb": "nm0715953", "role": "Sheriff of Rottingham"},
                {"name": "Amy Yasbeck", "imdb": "nm0001865", "role": "Marian"}
      ]
    }
  }
}


my_box = Box(movie_data)

my_box.movies.Spaceballs.rating
'PG'

my_box.movies.Spaceballs.Stars[0].name
'Mel Brooks'

my_box.movies.Spaceballs.Stars[0]
# <Box: {'name': 'Mel Brooks', 'imdb': 'nm0000316', 'role': 'President Skroob'}>

Box is a creation I made over three years ago, originally in the reusables code base named Namespace, inspired by JavaScript Object access methods.

Install is super simple:

pip install python-box

Or just grab the file box.py directly from the github project.

Every Box is usable as a drop in replacement to dictionaries in 99%* of cases. And every time you add a dictionary or list to a Box object, they become Box (subclass of dict) or BoxList (subclass of list) objects as well.

type(my_box)
# box.Box
assert isinstance(my_box, dict)

type(my_box.movies.Spaceballs.Stars)
# box.BoxList
assert isinstance(my_box.movies.Spaceballs.Stars, list)

my_box.movies.Spaceballs.Stars[0].additional_info = {'Birth name': 'Melvin Kaminsky', 'Birthday': "05/28/1926"}

my_box.movies.Spaceballs.Stars[0].additional_info
# <Box: {'Birth name': 'Melvin Kaminsky', 'Birthday': '05/28/1926'}>

At any level you can change a Box object back into a standard dictionary.

my_box.movies.Spaceballs.to_dict()

{'Director': 'Mel Brooks',
 'Stars': [
  {'additional_info': {'Birth name': 'Melvin Kaminsky', 'Birthday': '05/28/1926'},
   'imdb': 'nm0000316',
   'name': 'Mel Brooks',
   'role': 'President Skroob'},
  {'imdb': 'nm0001006', 'name': 'John Candy', 'role': 'Barf'},
  {'imdb': 'nm0001548', 'name': 'Rick Moranis', 'role': 'Dark Helmet'},
  {'imdb': 'nm0000597', 'name': 'Bill Pullman', 'role': 'Lone Starr'}],
 'imdb_stars': 7.1,
 'length': 96,
 'rating': 'PG'}

You can also run to_list() on lists in the Box to return them to a standard list, with all inner Box and BoxList objects transformed back to normal.

Box also has built in functions for dealing with json and yaml**.

my_box.movies.Spaceballs.to_json()

# {
#    "imdb_stars": 7.1,
#    "rating": "PG",
#    "length": 96,
#    "Director": "Mel Brooks",
#    "Stars": [
# ...


my_box.movies.Spaceballs.to_yaml()

# Director: Mel Brooks
# imdb_stars: 7.1
# length: 96
# rating: PG
# Stars:
# - imdb: nm0000316
#   name: Mel Brooks
#   role: President Skroob
# ...

Calling a Box object will return it’s keys. It’s also possible to access the attributes the standard dictionary method, which is required for keys that are numeric or have spaces.

my_box.movies()
# ('Spaceballs', 'Robin Hood: Men in Tights')

my_box.movies['Robin Hood: Men in Tights']
# <Box: {'imdb_stars': 6.7, 'rating': 'PG-13', 'length': 104, ...

Unlike addict it does not act as a default dictionary, so you will get built-in errors if you try to access something that isn’t there.

my_box.tv_shows

# Traceback (most recent call last):
# ...
# AttributeError: tv_shows

Another power previously mentioned is that you can add dictionaries into lists and they will automatically be converted into Box objects.

my_box.movies.Spaceballs.Stars.append(
    {"name": "Bill Pullman", "imdb": "nm0000597", "role": "Lone Starr"})

my_box.moves.Spaceballs.Stars[-1].name
'Bill Pullman'

It also protects itself from having its functions overwritten accidentally.

my_box.to_dict = '3'
# AttributeError: Key name 'to_dict' is protected

Box is also a substitute for the Namespace used by argparse, making it super easy to convert incoming arguments to a dict if wanted. This allows incoming arguments to be easily passed to function arguments.

import argparse
from box import Box

parser = argparse.ArgumentParser()
parser.add_argument('floats', metavar='N', type=float, nargs='+')
parser.add_argument("-v", "--verbosity", action="count", default=0)

args = parser.parse_args(['1', '2', '3', '-vv'], namespace=Box())

print(args.to_dict())
{'floats': [1.0, 2.0, 3.0], 'verbosity': 2}


def example_func(floats, verbosity):
    print(verbosity)

example_func(**args)
2

If you have any questions, suggestions or feedback, please open a github issue and let me know!

Hope you enjoy!

Caveats

*  Based off nothing but pure guess and personal experience. Only time drop in replacement doesn’t work is when converting or dumping. So make sure do use  first for those cases.  

** If you don’t have PyYAML installed, the to_yaml function will not be available.