133 lines
3.5 KiB
Python

"""
schedule2.py: traversing OSCON schedule data
>>> import shelve
>>> db = shelve.open(DB_NAME)
>>> if CONFERENCE not in db: load_db(db)
# BEGIN SCHEDULE2_DEMO
>>> DbRecord.set_db(db) # <1>
>>> event = DbRecord.fetch('event.33950') # <2>
>>> event # <3>
<Event 'There *Will* Be Bugs'>
>>> event.venue # <4>
<DbRecord serial='venue.1449'>
>>> event.venue.name # <5>
'Portland 251'
>>> for spkr in event.speakers: # <6>
... print('{0.serial}: {0.name}'.format(spkr))
...
speaker.3471: Anna Martelli Ravenscroft
speaker.5199: Alex Martelli
# END SCHEDULE2_DEMO
>>> db.close()
"""
# BEGIN SCHEDULE2_RECORD
import warnings
import inspect # <1>
import osconfeed
DB_NAME = 'data/schedule2_db' # <2>
CONFERENCE = 'conference.115'
class Record:
def __init__(self, **kwargs):
self.__dict__.update(kwargs)
def __eq__(self, other): # <3>
if isinstance(other, Record):
return self.__dict__ == other.__dict__
else:
return NotImplemented
# END SCHEDULE2_RECORD
# BEGIN SCHEDULE2_DBRECORD
class MissingDatabaseError(RuntimeError):
"""Raised when a database is required but was not set.""" # <1>
class DbRecord(Record): # <2>
__db = None # <3>
@staticmethod # <4>
def set_db(db):
DbRecord.__db = db # <5>
@staticmethod # <6>
def get_db():
return DbRecord.__db
@classmethod # <7>
def fetch(cls, ident):
db = cls.get_db()
try:
return db[ident] # <8>
except TypeError:
if db is None: # <9>
msg = "database not set; call '{}.set_db(my_db)'"
raise MissingDatabaseError(msg.format(cls.__name__))
else: # <10>
raise
def __repr__(self):
if hasattr(self, 'serial'): # <11>
cls_name = self.__class__.__name__
return '<{} serial={!r}>'.format(cls_name, self.serial)
else:
return super().__repr__() # <12>
# END SCHEDULE2_DBRECORD
# BEGIN SCHEDULE2_EVENT
class Event(DbRecord): # <1>
@property
def venue(self):
key = 'venue.{}'.format(self.venue_serial)
return self.__class__.fetch(key) # <2>
@property
def speakers(self):
if not hasattr(self, '_speaker_objs'): # <3>
spkr_serials = self.__dict__['speakers'] # <4>
fetch = self.__class__.fetch # <5>
self._speaker_objs = [fetch('speaker.{}'.format(key))
for key in spkr_serials] # <6>
return self._speaker_objs # <7>
def __repr__(self):
if hasattr(self, 'name'): # <8>
cls_name = self.__class__.__name__
return '<{} {!r}>'.format(cls_name, self.name)
else:
return super().__repr__() # <9>
# END SCHEDULE2_EVENT
# BEGIN SCHEDULE2_LOAD
def load_db(db):
raw_data = osconfeed.load()
warnings.warn('loading ' + DB_NAME)
for collection, rec_list in raw_data['Schedule'].items():
record_type = collection[:-1] # <1>
cls_name = record_type.capitalize() # <2>
cls = globals().get(cls_name, DbRecord) # <3>
if inspect.isclass(cls) and issubclass(cls, DbRecord): # <4>
factory = cls # <5>
else:
factory = DbRecord # <6>
for record in rec_list: # <7>
key = '{}.{}'.format(record_type, record['serial'])
record['serial'] = key
db[key] = factory(**record) # <8>
# END SCHEDULE2_LOAD