example-code-2e/05-data-classes/dataclass/resource.py
2021-08-07 00:44:01 -03:00

88 lines
2.7 KiB
Python

"""
Media resource description class with subset of the Dublin Core fields.
Default field values:
>>> r = Resource('0')
>>> r # doctest: +NORMALIZE_WHITESPACE
Resource(identifier='0', title='<untitled>', creators=[], date=None,
type=<ResourceType.BOOK: 1>, description='', language='', subjects=[])
A complete resource record:
# tag::DOCTEST[]
>>> description = 'Improving the design of existing code'
>>> book = Resource('978-0-13-475759-9', 'Refactoring, 2nd Edition',
... ['Martin Fowler', 'Kent Beck'], date(2018, 11, 19),
... ResourceType.BOOK, description, 'EN',
... ['computer programming', 'OOP'])
>>> book # doctest: +NORMALIZE_WHITESPACE
Resource(identifier='978-0-13-475759-9', title='Refactoring, 2nd Edition',
creators=['Martin Fowler', 'Kent Beck'], date=datetime.date(2018, 11, 19),
type=<ResourceType.BOOK: 1>, description='Improving the design of existing code',
language='EN', subjects=['computer programming', 'OOP'])
# end::DOCTEST[]
"""
# tag::DATACLASS[]
from dataclasses import dataclass, field
from typing import Optional
from enum import Enum, auto
from datetime import date
class ResourceType(Enum): # <1>
BOOK = auto()
EBOOK = auto()
VIDEO = auto()
@dataclass
class Resource:
"""Media resource description."""
identifier: str # <2>
title: str = '<untitled>' # <3>
creators: list[str] = field(default_factory=list)
date: Optional[date] = None # <4>
type: ResourceType = ResourceType.BOOK # <5>
description: str = ''
language: str = ''
subjects: list[str] = field(default_factory=list)
# end::DATACLASS[]
from typing import TypedDict
class ResourceDict(TypedDict):
identifier: str
title: str
creators: list[str]
date: Optional[date]
type: ResourceType
description: str
language: str
subjects: list[str]
if __name__ == '__main__':
r = Resource('0')
description = 'Improving the design of existing code'
book = Resource('978-0-13-475759-9', 'Refactoring, 2nd Edition',
['Martin Fowler', 'Kent Beck'], date(2018, 11, 19),
ResourceType.BOOK, description,
'EN', ['computer programming', 'OOP'])
print(book)
book_dict: ResourceDict = {
'identifier': '978-0-13-475759-9',
'title': 'Refactoring, 2nd Edition',
'creators': ['Martin Fowler', 'Kent Beck'],
'date': date(2018, 11, 19),
'type': ResourceType.BOOK,
'description': 'Improving the design of existing code',
'language': 'EN',
'subjects': ['computer programming', 'OOP']}
book2 = Resource(**book_dict)
print(book == book2)