jsons._lizers_impl._get_parents() - Code Metrics - Inspection of "Merge pull request #49 from ramonhagenaars/Release..." - ramonhagenaars/jsons - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 7be5b2...0ef053 )

by Ramon

created 2019-04-22 18:49 UTC

jsons._lizers_impl._get_parents() A

↳ Parent: jsons._lizers_impl

Complexity

Conditions

Size

Total Lines	17
Code Lines	10

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
eloc	10
dl	0
loc	17
rs	9.9
c	0
b	0
f	0
cc	4
nop	2

"""
PRIVATE MODULE: do not import (from) it directly.

This module contains functionality for setting and getting serializers and
deserializers.
"""
from typing import Optional, Dict, Sequence, Union
from jsons._common_impl import StateHolder, get_class_name
from jsons._compatibility_impl import get_naked_class


def set_serializer(
        func: callable,
        cls: Union[type, Sequence[type]],
        high_prio: bool = True,
        fork_inst: type = StateHolder) -> None:
    """
    Set a serializer function for the given type. You may override the default
    behavior of ``jsons.load`` by setting a custom serializer.

    The ``func`` argument must take one argument (i.e. the object that is to be
    serialized) and also a ``kwargs`` parameter. For example:

    >>> def func(obj, **kwargs):
    ...    return dict()

    You may ask additional arguments between ``cls`` and ``kwargs``.

    :param func: the serializer function.
    :param cls: the type or sequence of types this serializer can handle.
    :param high_prio: determines the order in which is looked for the callable.
    :param fork_inst: if given, it uses this fork of ``JsonSerializable``.
    :return: None.
    """
    if isinstance(cls, Sequence):
        for cls_ in cls:
            set_serializer(func, cls_, high_prio, fork_inst)
    elif cls:
        index = 0 if high_prio else len(fork_inst._classes_serializers)
        fork_inst._classes_serializers.insert(index, cls)
        cls_name = get_class_name(cls, fork_inst=fork_inst,
                                  fully_qualified=True)
        fork_inst._serializers[cls_name.lower()] = func
    else:
        fork_inst._serializers['nonetype'] = func


def set_deserializer(
        func: callable,
        cls: Union[type, Sequence[type]],
        high_prio: bool = True,
        fork_inst: type = StateHolder) -> None:
    """
    Set a deserializer function for the given type. You may override the
    default behavior of ``jsons.dump`` by setting a custom deserializer.

    The ``func`` argument must take two arguments (i.e. the dict containing the
    serialized values and the type that the values should be deserialized into)
    and also a ``kwargs`` parameter. For example:

    >>> def func(dict_, cls, **kwargs):
    ...    return cls()

    You may ask additional arguments between ``cls`` and ``kwargs``.

    :param func: the deserializer function.
    :param cls: the type or sequence of types this serializer can handle.
    :param high_prio: determines the order in which is looked for the callable.
    :param fork_inst: if given, it uses this fork of ``JsonSerializable``.
    :return: None.
    """
    if isinstance(cls, Sequence):
        for cls_ in cls:
            set_deserializer(func, cls_, high_prio, fork_inst)
    elif cls:
        index = 0 if high_prio else len(fork_inst._classes_deserializers)
        fork_inst._classes_deserializers.insert(index, cls)
        cls_name = get_class_name(cls, fork_inst=fork_inst,
                                  fully_qualified=True)
        fork_inst._deserializers[cls_name.lower()] = func
    else:
        fork_inst._deserializers['nonetype'] = func


def get_serializer(
        cls: type,
        fork_inst: Optional[type] = StateHolder) -> callable:
    """
    Return the serializer function that would be used for the given ``cls``.
    :param cls: the type for which a serializer is to be returned.
    :param fork_inst: if given, it uses this fork of ``JsonSerializable``.
    :return: a serializer function.
    """
    serializer = _get_lizer(cls, fork_inst._serializers,
                            fork_inst._classes_serializers, fork_inst)
    return serializer


def get_deserializer(
        cls: type,
        fork_inst: Optional[type] = StateHolder) -> callable:
    """
    Return the deserializer function that would be used for the given ``cls``.
    :param cls: the type for which a deserializer is to be returned.
    :param fork_inst: if given, it uses this fork of ``JsonSerializable``.
    :return: a deserializer function.
    """
    deserializer = _get_lizer(cls, fork_inst._deserializers,
                              fork_inst._classes_deserializers, fork_inst)
    return deserializer


def _get_lizer(
        cls: type,
        lizers: Dict[str, callable],
        classes_lizers: list,
        fork_inst: type,
        recursive: bool = False) -> callable:
    cls_name = get_class_name(cls, str.lower, fork_inst=fork_inst,
                              fully_qualified=True)
    lizer = (lizers.get(cls_name, None)
             or _get_lizer_by_parents(cls, lizers, classes_lizers, fork_inst))
    if not lizer and not recursive:
        return _get_lizer(cls.__supertype__, lizers,
                          classes_lizers, fork_inst, True)
    return lizer


def _get_lizer_by_parents(
        cls: type,
        lizers: Dict[str, callable],
        classes_lizers: list,
        fork_inst: type) -> callable:
    result = None
    parents = _get_parents(cls, classes_lizers)
    if parents:
        pname = get_class_name(parents[0], str.lower, fork_inst=fork_inst,
                               fully_qualified=True)
        result = lizers[pname]
    return result


def _get_parents(cls: type, lizers: list) -> list:
    """
    Return a list of serializers or deserializers that can handle a parent
    of ``cls``.
    :param cls: the type that
    :param lizers: a list of serializers or deserializers.
    :return: a list of serializers or deserializers.
    """
    parents = []
    naked_cls = get_naked_class(cls)
    for cls_ in lizers:
        try:
            if issubclass(naked_cls, cls_):
                parents.append(cls_)
        except (TypeError, AttributeError):
            pass  # Some types do not support `issubclass` (e.g. Union).
    return parents


1			"""
2			PRIVATE MODULE: do not import (from) it directly.
3
4			This module contains functionality for setting and getting serializers and
5			deserializers.
6			"""
7			from typing import Optional, Dict, Sequence, Union
8			from jsons._common_impl import StateHolder, get_class_name
9			from jsons._compatibility_impl import get_naked_class
10
11
12			def set_serializer(
13			func: callable,
14			cls: Union[type, Sequence[type]],
15			high_prio: bool = True,
16			fork_inst: type = StateHolder) -> None:
17			"""
18			Set a serializer function for the given type. You may override the default
19			behavior of ``jsons.load`` by setting a custom serializer.
20
21			The ``func`` argument must take one argument (i.e. the object that is to be
22			serialized) and also a ``kwargs`` parameter. For example:
23
24			>>> def func(obj, **kwargs):
25			... return dict()
26
27			You may ask additional arguments between ``cls`` and ``kwargs``.
28
29			:param func: the serializer function.
30			:param cls: the type or sequence of types this serializer can handle.
31			:param high_prio: determines the order in which is looked for the callable.
32			:param fork_inst: if given, it uses this fork of ``JsonSerializable``.
33			:return: None.
34			"""
35			if isinstance(cls, Sequence):
36			for cls_ in cls:
37			set_serializer(func, cls_, high_prio, fork_inst)
38			elif cls:
39			index = 0 if high_prio else len(fork_inst._classes_serializers)
40			fork_inst._classes_serializers.insert(index, cls)
41			cls_name = get_class_name(cls, fork_inst=fork_inst,
42			fully_qualified=True)
43			fork_inst._serializers[cls_name.lower()] = func
44			else:
45			fork_inst._serializers['nonetype'] = func
46
47
48			def set_deserializer(
49			func: callable,
50			cls: Union[type, Sequence[type]],
51			high_prio: bool = True,
52			fork_inst: type = StateHolder) -> None:
53			"""
54			Set a deserializer function for the given type. You may override the
55			default behavior of ``jsons.dump`` by setting a custom deserializer.
56
57			The ``func`` argument must take two arguments (i.e. the dict containing the
58			serialized values and the type that the values should be deserialized into)
59			and also a ``kwargs`` parameter. For example:
60
61			>>> def func(dict_, cls, **kwargs):
62			... return cls()
63
64			You may ask additional arguments between ``cls`` and ``kwargs``.
65
66			:param func: the deserializer function.
67			:param cls: the type or sequence of types this serializer can handle.
68			:param high_prio: determines the order in which is looked for the callable.
69			:param fork_inst: if given, it uses this fork of ``JsonSerializable``.
70			:return: None.
71			"""
72			if isinstance(cls, Sequence):
73			for cls_ in cls:
74			set_deserializer(func, cls_, high_prio, fork_inst)
75			elif cls:
76			index = 0 if high_prio else len(fork_inst._classes_deserializers)
77			fork_inst._classes_deserializers.insert(index, cls)
78			cls_name = get_class_name(cls, fork_inst=fork_inst,
79			fully_qualified=True)
80			fork_inst._deserializers[cls_name.lower()] = func
81			else:
82			fork_inst._deserializers['nonetype'] = func
83
84
85			def get_serializer(
86			cls: type,
87			fork_inst: Optional[type] = StateHolder) -> callable:
88			"""
89			Return the serializer function that would be used for the given ``cls``.
90			:param cls: the type for which a serializer is to be returned.
91			:param fork_inst: if given, it uses this fork of ``JsonSerializable``.
92			:return: a serializer function.
93			"""
94			serializer = _get_lizer(cls, fork_inst._serializers,
95			fork_inst._classes_serializers, fork_inst)
96			return serializer
97
98
99			def get_deserializer(
100			cls: type,
101			fork_inst: Optional[type] = StateHolder) -> callable:
102			"""
103			Return the deserializer function that would be used for the given ``cls``.
104			:param cls: the type for which a deserializer is to be returned.
105			:param fork_inst: if given, it uses this fork of ``JsonSerializable``.
106			:return: a deserializer function.
107			"""
108			deserializer = _get_lizer(cls, fork_inst._deserializers,
109			fork_inst._classes_deserializers, fork_inst)
110			return deserializer
111
112
113			def _get_lizer(
114			cls: type,
115			lizers: Dict[str, callable],
116			classes_lizers: list,
117			fork_inst: type,
118			recursive: bool = False) -> callable:
119			cls_name = get_class_name(cls, str.lower, fork_inst=fork_inst,
120			fully_qualified=True)
121			lizer = (lizers.get(cls_name, None)
122			or _get_lizer_by_parents(cls, lizers, classes_lizers, fork_inst))
123			if not lizer and not recursive:
124			return _get_lizer(cls.__supertype__, lizers,
125			classes_lizers, fork_inst, True)
126			return lizer
127
128
129			def _get_lizer_by_parents(
130			cls: type,
131			lizers: Dict[str, callable],
132			classes_lizers: list,
133			fork_inst: type) -> callable:
134			result = None
135			parents = _get_parents(cls, classes_lizers)
136			if parents:
137			pname = get_class_name(parents[0], str.lower, fork_inst=fork_inst,
138			fully_qualified=True)
139			result = lizers[pname]
140			return result
141
142
143			def _get_parents(cls: type, lizers: list) -> list:
144			"""
145			Return a list of serializers or deserializers that can handle a parent
146			of ``cls``.
147			:param cls: the type that
148			:param lizers: a list of serializers or deserializers.
149			:return: a list of serializers or deserializers.
150			"""
151			parents = []
152			naked_cls = get_naked_class(cls)
153			for cls_ in lizers:
154			try:
155			if issubclass(naked_cls, cls_):
156			parents.append(cls_)
157			except (TypeError, AttributeError):
158			pass # Some types do not support `issubclass` (e.g. Union).
159			return parents
160

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jsons._lizers_impl._get_parents() A

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