17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213 | class PythonObjectJson(object):
"""Base Python Object with JSON serialization and deserialization compatibility."""
"""Instantiate the Python Package Template example class.
Args:
example_init_parameter (str): Example class init parameter for the Python Package Template.
Attributes:
example_init_parameter (str): Example class attribute for the Python Package Template.
"""
def __init__(self, **kwargs):
"""Instantiate the PythonObjectJson class with all keyword arguments.
Args:
kwargs (dict): Key/value pairs to be passed to the PythonObjectJson class.
"""
vars(self).update(kwargs)
def __str__(self):
return self.to_json_str()
def __repr__(self):
return self.to_json_str()
@staticmethod
def _complex_json_handler(obj: Any) -> Any:
"""Custom handler to allow custom objects to be serialized into JSON.
Args:
obj (Any): Custom object to be serialized into JSON.
Returns:
obj (Any): Serializable version of the custom object.
"""
if hasattr(obj, "_serialized"):
# noinspection PyProtectedMember
return obj._serialized()
else:
try:
return str(obj)
except TypeError:
raise TypeError(
f"Object of type {type(obj)} with value of {repr(obj)} is not JSON serializable."
)
def _base_subclasses(self) -> Dict[str, Any]:
"""Create dict with snakecase keys derived from custom object type camelcase class names.
Returns:
dict[str, Any]: Dictionary with snakecase strings of all subclasses of PythonObjectJson as keys and
subclasses as values.
"""
return {
cls.__name__.lower(): cls
for cls in self.__class__.__mro__[-2].__subclasses__()
}
def _clean_data_dict(self) -> Dict[str, Any]:
"""Recursive method to un-type custom class type objects for serialization.
Returns:
dict[str, Any]: Dictionary that extracts serializable data from custom objects.
"""
clean_dict = {}
for k, v in vars(self).items():
# noinspection PyProtectedMember
clean_dict[k] = (
v._clean_data_dict()
if type(v) in self._base_subclasses().values()
else v
)
return clean_dict
def _serialized(self) -> Dict[str, Any]:
"""Pack up all object content into nested dictionaries for JSON serialization.
Returns:
dict[str, Any]: Serializable dictionary.
"""
serializable_dict = dict()
for att, val in self._clean_data_dict().items():
if hasattr(val, "_serialized"):
# noinspection PyProtectedMember
serializable_dict[att] = val._serialized()
elif isinstance(val, set):
serializable_dict[att] = list(val)
else:
serializable_dict[att] = val
return {self.__class__.__name__.lower(): serializable_dict}
def _deserialized(self, json_data: Any) -> Any:
"""
Args:
json_data (Any): JSON data to be deserialized.
Returns:
obj (Any): Object deserialized from JSON.
"""
if isinstance(json_data, list):
return [self._deserialized(item) for item in json_data]
elif isinstance(json_data, dict):
base_subclasses = self._base_subclasses()
# noinspection PyUnboundLocalVariable
if (
len(json_data) == 1
and (single_key := next(iter(json_data.keys())))
and single_key in base_subclasses
):
# noinspection PyPep8Naming
ClassObject = self._base_subclasses()[single_key]
class_args = getfullargspec(ClassObject.__init__).args[1:]
class_attributes: Dict[str, Any] = json_data[single_key]
class_instance = ClassObject(
**{
k: self._deserialized(v)
for k, v in class_attributes.items()
if k in class_args
}
)
vars(class_instance).update(
{k: self._deserialized(v) for k, v in class_attributes.items()}
)
return class_instance
else:
return {k: self._deserialized(v) for k, v in json_data.items()}
else:
return json_data
def to_json_str(self) -> str:
"""Serialize the class object to a JSON string.
Returns:
str: JSON string derived from the serializable version of the class object.
"""
return json.dumps(
self._serialized(),
ensure_ascii=False,
indent=2,
default=self._complex_json_handler,
)
def save_to_json_file(self, json_file_path: Path) -> None:
"""Save the class object to a JSON file.
Args:
json_file_path (Path): Target JSON file path to which the class object will be saved.
Returns:
None
"""
if not json_file_path.exists():
json_file_path.parent.mkdir(parents=True, exist_ok=True)
with open(json_file_path, "w", encoding="utf-8") as json_file_out:
# TODO: fix incorrect file input type warning for json.dump from PyCharm bug https://youtrack.jetbrains.com/issue/PY-73050/openfile.txt-r-return-type-should-be-inferred-as-TextIOWrapper-instead-of-TextIO
# noinspection PyTypeChecker
json.dump(
self._serialized(),
json_file_out,
indent=2,
default=self._complex_json_handler,
ensure_ascii=False,
)
def load_from_json_file(self, json_file_path: Path) -> None:
"""Load the class object from a JSON file.
Args:
json_file_path (Path): Target JSON file path from which the class object will be loaded.
Returns:
None
"""
if not json_file_path.exists():
raise FileNotFoundError(
f"File {json_file_path} does not exist. Unable to load saved data."
)
with open(json_file_path, "r", encoding="utf-8") as json_file_in:
loaded_class_instance = self._deserialized(json.load(json_file_in))
vars(self).update(**vars(loaded_class_instance))
|