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#!/usr/bin/env PYTHONHASHSEED=1234 python3
# Copyright 2014-2024 Brett Slatkin, Pearson Education Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
### 책 예제에 맞는 환경 설정을 시작함
import random
random.seed(1234)
import logging
from pprint import pprint
from sys import stdout as STDOUT
# 모든 출력을 임시 디렉터리로 보냄
import atexit
import gc
import io
import os
import tempfile
TEST_DIR = tempfile.TemporaryDirectory()
atexit.register(TEST_DIR.cleanup)
# 윈도우에서 프로세스가 제대로 종료되도록 함
OLD_CWD = os.getcwd()
atexit.register(lambda: os.chdir(OLD_CWD))
os.chdir(TEST_DIR.name)
def close_open_files():
everything = gc.get_objects()
for obj in everything:
if isinstance(obj, io.IOBase):
obj.close()
atexit.register(close_open_files)
### 책 예제에 맞는 환경설정 끝
print("아이템 63")
print("Example 1")
import json
class Serializable:
def __init__(self, *args):
self.args = args
def serialize(self):
return json.dumps({"args": self.args})
print("Example 2")
class Point2D(Serializable):
def __init__(self, x, y):
super().__init__(x, y)
self.x = x
self.y = y
def __repr__(self):
return f"Point2D({self.x}, {self.y})"
point = Point2D(5, 3)
print("객체: ", point)
print("직렬화:", point.serialize())
print("Example 3")
class Deserializable(Serializable):
@classmethod
def deserialize(cls, json_data):
params = json.loads(json_data)
return cls(*params["args"])
print("Example 4")
class BetterPoint2D(Deserializable):
def __init__(self, x, y):
super().__init__(x, y)
self.x = x
self.y = y
def __repr__(self):
return f"Point2D({self.x}, {self.y})"
before = BetterPoint2D(5, 3)
print("객체: ", before)
data = before.serialize()
print("직렬화: ", data)
after = BetterPoint2D.deserialize(data)
print("역직렬화:", after)
print("Example 5")
class BetterSerializable:
def __init__(self, *args):
self.args = args
def serialize(self):
return json.dumps(
{
"class": self.__class__.__name__,
"args": self.args,
}
)
def __repr__(self):
name = self.__class__.__name__
args_str = ", ".join(str(x) for x in self.args)
return f"{name}({args_str})"
print("Example 6")
REGISTRY = {}
def register_class(target_class):
REGISTRY[target_class.__name__] = target_class
def deserialize(data):
params = json.loads(data)
name = params["class"]
target_class = REGISTRY[name]
return target_class(*params["args"])
print("Example 7")
class EvenBetterPoint2D(BetterSerializable):
def __init__(self, x, y):
super().__init__(x, y)
self.x = x
self.y = y
register_class(EvenBetterPoint2D)
print("Example 8")
before = EvenBetterPoint2D(5, 3)
print("객체: ", before)
data = before.serialize()
print("직렬화: ", data)
after = deserialize(data)
print("역직렬화:", after)
print("Example 9")
class Point3D(BetterSerializable):
def __init__(self, x, y, z):
super().__init__(x, y, z)
self.x = x
self.y = y
self.z = z
# register_class 호출을 잊어버렸다. 이런!
print("Example 10")
try:
point = Point3D(5, 9, -4)
data = point.serialize()
deserialize(data)
except:
logging.exception('이 예외가 발생해야 함')
else:
assert False
print("Example 11")
class Meta(type):
def __new__(meta, name, bases, class_dict):
cls = type.__new__(meta, name, bases, class_dict)
register_class(cls)
return cls
class RegisteredSerializable(BetterSerializable, metaclass=Meta):
pass
print("Example 12")
class Vector3D(RegisteredSerializable):
def __init__(self, x, y, z):
super().__init__(x, y, z)
self.x, self.y, self.z = x, y, z
before = Vector3D(10, -7, 3)
print("객체: ", before)
data = before.serialize()
print("직렬화: ", data)
print("역직렬화:", deserialize(data))
print("Example 13")
class BetterRegisteredSerializable(BetterSerializable):
def __init_subclass__(cls):
super().__init_subclass__()
register_class(cls)
class Vector1D(BetterRegisteredSerializable):
def __init__(self, magnitude):
super().__init__(magnitude)
self.magnitude = magnitude
print("Example 14")
before = Vector1D(6)
print("객체: ", before)
data = before.serialize()
print("직렬화: ", data)
print("역직렬화:", deserialize(data))