"""

explore1.py: Script to explore the OSCON schedule feed

>>> import json

>>> raw_feed = json.load(open('data/osconfeed.json'))

>>> feed = FrozenJSON(raw_feed)

>>> len(feed.Schedule.speakers)

357

>>> sorted(feed.Schedule.keys())

['conferences', 'events', 'speakers', 'venues']

>>> for key, value in sorted(feed.Schedule.items()):

... print(f'{len(value):3} {key}')

...

1 conferences

484 events

357 speakers

53 venues

>>> feed.Schedule.speakers[-1].name

'Carina C. Zona'

>>> talk = feed.Schedule.events[40]

>>> type(talk)

<class 'explore1.FrozenJSON'>

>>> talk.name

'There *Will* Be Bugs'

>>> talk.speakers

[3471, 5199]

>>> talk.flavor

Traceback (most recent call last):

...

KeyError: 'flavor'

Handle keywords by appending a `_`.

# tag::EXPLORE1_DEMO[]

>>> grad = FrozenJSON({'name': 'Jim Bo', 'class': 1982})

>>> grad.name

'Jim Bo'

>>> grad.class_

1982

# end::EXPLORE1_DEMO[]

"""

from collections import abc

import keyword

class FrozenJSON:

"""A read-only façade for navigating a JSON-like object

using attribute notation

"""

# tag::EXPLORE1[]

def __init__(self, mapping):

self.__data = {}

for key, value in mapping.items():

if keyword.iskeyword(key): # <1>

key += '_'

self.__data[key] = value

# end::EXPLORE1[]

def __getattr__(self, name):

try:

return getattr(self.__data, name)

except AttributeError:

return FrozenJSON.build(self.__data[name])

def __dir__(self): # <5>

return self.__data.keys()

@classmethod

def build(cls, obj):

if isinstance(obj, abc.Mapping):

return cls(obj)

elif isinstance(obj, abc.MutableSequence):

return [cls.build(item) for item in obj]

else: # <8>

return obj