jsons._common_impl.get_cls_and_meta() - Code Metrics - ramonhagenaars/jsons - Measure and Improve Code Quality continuously with Scrutinizer

jsons._common_impl.get_cls_and_meta() A
last analyzed 2022-06-09 19:52 UTC

↳ Parent: jsons._common_impl

Complexity

Conditions

Size

Total Lines	8
Code Lines	8

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
eloc	8
dl	0
loc	8
rs	10
c	0
b	0
f	0
cc	3
nop	2

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

This module contains implementations of common functionality that can be used
throughout `jsons`.
"""
import builtins
import warnings
from importlib import import_module
from typing import Callable, Optional, Tuple, TypeVar, Any

from jsons._cache import cached
from jsons._compatibility_impl import get_union_params
from jsons.exceptions import UnknownClassError

NoneType = type(None)
JSON_KEYS = (str, int, float, bool, NoneType)
VALID_TYPES = (str, int, float, bool, list, tuple, set, dict, NoneType)
META_ATTR = '-meta'  # The name of the attribute holding meta info.
T = TypeVar('T')


class StateHolder:
    """
    This class holds the registered serializers and deserializers.
    """
    _fork_counter = 0
    _classes_serializers = list()
    _classes_deserializers = list()
    _serializers = dict()
    _deserializers = dict()
    _validators = dict()
    _classes_validators = list()
    _announced_classes = dict()
    _suppress_warnings = False
    _suppressed_warnings = set()

    @classmethod
    def _warn(cls, msg, code, *args, **kwargs):
        if not cls._suppress_warnings and code not in cls._suppressed_warnings:
            msg_ = ('{} Use suppress_warning({}) or suppress_warnings(True) to '
                    'turn off this message.'.format(msg, code))
            warnings.warn(msg_, *args, **kwargs)


@cached
def get_class_name(cls: type,
                   transformer: Optional[Callable[[str], str]] = None,
                   fully_qualified: bool = False) -> Optional[str]:
    """
    Return the name of a class.
    :param cls: the class of which the name if to be returned.
    :param transformer: any string transformer, e.g. ``str.lower``.
    :param fully_qualified: if ``True`` return the fully qualified name (i.e.
    complete with module name).
    :return: the name of ``cls``, transformed if a transformer is given.
    """
    transformer = transformer or (lambda x: x)
    cls_name = _get_special_cases(cls)
    if cls_name:
        return transformer(cls_name)
    cls_name = _get_simple_name(cls)
    if fully_qualified:
        module = _get_module(cls)
        if module:
            cls_name = '{}.{}'.format(module, cls_name)
    cls_name = transformer(cls_name)
    return cls_name


def _get_special_cases(cls: type):
    if (hasattr(cls, '__qualname__')
            and cls.__qualname__ == 'NewType.<locals>.new_type'):
        return cls.__name__


def get_cls_from_str(cls_str: str, source: object, fork_inst) -> type:
    cls = getattr(builtins, cls_str, None)
    if cls:
        return cls
    if '[' in cls_str and ']' in cls_str:
        return _get_generic_cls_from_str(cls_str, source, fork_inst)
    try:
        splitted = cls_str.split('.')
        module_name = '.'.join(splitted[:-1])
        cls_name = splitted[-1]
        cls_module = import_module(module_name)
        cls = getattr(cls_module, cls_name)
    except (ImportError, AttributeError, ValueError):
        cls = _lookup_announced_class(cls_str, source, fork_inst)
    return cls


def _get_generic_cls_from_str(cls_str: str, source: object, fork_inst) -> type:
    # If cls_str represents a generic type, try to parse the sub types.
    origin_str, subtypes_str = cls_str.split('[')
    subtypes_str = subtypes_str[0:-1]  # Remove the ']'.
    origin = get_cls_from_str(origin_str, source, fork_inst)
    subtypes = [get_cls_from_str(s.strip(), source, fork_inst)
                for s in subtypes_str.split(',')]
    return origin[tuple(subtypes)]


def determine_precedence(
        cls: type,
        cls_from_meta: type,
        cls_from_type: type,
        inferred_cls: bool):
    order = [cls, cls_from_meta, cls_from_type]
    if inferred_cls:
        # The type from a verbose dumped object takes precedence over an
        # inferred type (e.g. T in List[T]).
        order = [cls_from_meta, cls, cls_from_type]
    # Now to return the first element in the order that holds a value.
    for elem in order:
        if elem:
            return elem


def get_cls_and_meta(
        json_obj: object,
        fork_inst: type) -> Tuple[Optional[type], Optional[dict]]:
    if isinstance(json_obj, dict) and META_ATTR in json_obj:
        cls_str = json_obj[META_ATTR]['classes']['/']
        cls = get_cls_from_str(cls_str, json_obj, fork_inst)
        return cls, json_obj[META_ATTR]
    return None, None


def can_match_with_none(cls: type):
    # Return True if cls allows None; None is a valid value with the given cls.
    result = cls in (Any, object, None, NoneType)
    if not result:
        cls_name = get_class_name(cls).lower()
        result = (('union' in cls_name or 'optional' in cls_name)
                  and NoneType in get_union_params(cls))
    return result


def _lookup_announced_class(
        cls_str: str,
        source: object,
        fork_inst: type) -> type:
    cls = fork_inst._announced_classes.get(cls_str)
    if not cls:
        msg = ('Could not find a suitable type for "{}". Make sure it can be '
               'imported or that is has been announced.'.format(cls_str))
        raise UnknownClassError(msg, source, cls_str)
    return cls


def _get_simple_name(cls: type) -> str:
    if cls is None:
        cls = type(cls)
    cls_name = getattr(cls, '__name__', None)
    if not cls_name:
        cls_name = getattr(cls, '_name', None)
    if not cls_name:
        cls_name = repr(cls)
        cls_name = cls_name.split('[')[0]  # Remove generic types.
        cls_name = cls_name.split('.')[-1]  # Remove any . caused by repr.
        cls_name = cls_name.split(r"'>")[0]  # Remove any '>.
    return cls_name


def _get_module(cls: type) -> Optional[str]:
    builtin_module = str.__class__.__module__
    module = getattr(cls, '__module__', None)
    if module and module != builtin_module:
        return module


1			"""
2			PRIVATE MODULE: do not import (from) it directly.
3
4			This module contains implementations of common functionality that can be used
5			throughout `jsons`.
6			"""
7			import builtins
8			import warnings
9			from importlib import import_module
10			from typing import Callable, Optional, Tuple, TypeVar, Any
11
12			from jsons._cache import cached
13			from jsons._compatibility_impl import get_union_params
14			from jsons.exceptions import UnknownClassError
15
16			NoneType = type(None)
17			JSON_KEYS = (str, int, float, bool, NoneType)
18			VALID_TYPES = (str, int, float, bool, list, tuple, set, dict, NoneType)
19			META_ATTR = '-meta' # The name of the attribute holding meta info.
20			T = TypeVar('T')
21
22
23			class StateHolder:
24			"""
25			This class holds the registered serializers and deserializers.
26			"""
27			_fork_counter = 0
28			_classes_serializers = list()
29			_classes_deserializers = list()
30			_serializers = dict()
31			_deserializers = dict()
32			_validators = dict()
33			_classes_validators = list()
34			_announced_classes = dict()
35			_suppress_warnings = False
36			_suppressed_warnings = set()
37
38			@classmethod
39			def _warn(cls, msg, code, args, *kwargs):
40			if not cls._suppress_warnings and code not in cls._suppressed_warnings:
41			msg_ = ('{} Use suppress_warning({}) or suppress_warnings(True) to '
42			'turn off this message.'.format(msg, code))
43			warnings.warn(msg_, args, *kwargs)
44
45
46			@cached
47			def get_class_name(cls: type,
48			transformer: Optional[Callable[[str], str]] = None,
49			fully_qualified: bool = False) -> Optional[str]:
50			"""
51			Return the name of a class.
52			:param cls: the class of which the name if to be returned.
53			:param transformer: any string transformer, e.g. ``str.lower``.
54			:param fully_qualified: if ``True`` return the fully qualified name (i.e.
55			complete with module name).
56			:return: the name of ``cls``, transformed if a transformer is given.
57			"""
58			transformer = transformer or (lambda x: x)
59			cls_name = _get_special_cases(cls)
60			if cls_name:
61			return transformer(cls_name)
62			cls_name = _get_simple_name(cls)
63			if fully_qualified:
64			module = _get_module(cls)
65			if module:
66			cls_name = '{}.{}'.format(module, cls_name)
67			cls_name = transformer(cls_name)
68			return cls_name
69
70
71			def _get_special_cases(cls: type):
72			if (hasattr(cls, '__qualname__')
73			and cls.__qualname__ == 'NewType.<locals>.new_type'):
74			return cls.__name__
75
76
77			def get_cls_from_str(cls_str: str, source: object, fork_inst) -> type:
78			cls = getattr(builtins, cls_str, None)
79			if cls:
80			return cls
81			if '[' in cls_str and ']' in cls_str:
82			return _get_generic_cls_from_str(cls_str, source, fork_inst)
83			try:
84			splitted = cls_str.split('.')
85			module_name = '.'.join(splitted[:-1])
86			cls_name = splitted[-1]
87			cls_module = import_module(module_name)
88			cls = getattr(cls_module, cls_name)
89			except (ImportError, AttributeError, ValueError):
90			cls = _lookup_announced_class(cls_str, source, fork_inst)
91			return cls
92
93
94			def _get_generic_cls_from_str(cls_str: str, source: object, fork_inst) -> type:
95			# If cls_str represents a generic type, try to parse the sub types.
96			origin_str, subtypes_str = cls_str.split('[')
97			subtypes_str = subtypes_str[0:-1] # Remove the ']'.
98			origin = get_cls_from_str(origin_str, source, fork_inst)
99			subtypes = [get_cls_from_str(s.strip(), source, fork_inst)
100			for s in subtypes_str.split(',')]
101			return origin[tuple(subtypes)]
102
103
104			def determine_precedence(
105			cls: type,
106			cls_from_meta: type,
107			cls_from_type: type,
108			inferred_cls: bool):
109			order = [cls, cls_from_meta, cls_from_type]
110			if inferred_cls:
111			# The type from a verbose dumped object takes precedence over an
112			# inferred type (e.g. T in List[T]).
113			order = [cls_from_meta, cls, cls_from_type]
114			# Now to return the first element in the order that holds a value.
115			for elem in order:
116			if elem:
117			return elem
118
119
120			def get_cls_and_meta(
121			json_obj: object,
122			fork_inst: type) -> Tuple[Optional[type], Optional[dict]]:
123			if isinstance(json_obj, dict) and META_ATTR in json_obj:
124			cls_str = json_obj[META_ATTR]['classes']['/']
125			cls = get_cls_from_str(cls_str, json_obj, fork_inst)
126			return cls, json_obj[META_ATTR]
127			return None, None
128
129
130			def can_match_with_none(cls: type):
131			# Return True if cls allows None; None is a valid value with the given cls.
132			result = cls in (Any, object, None, NoneType)
133			if not result:
134			cls_name = get_class_name(cls).lower()
135			result = (('union' in cls_name or 'optional' in cls_name)
136			and NoneType in get_union_params(cls))
137			return result
138
139
140			def _lookup_announced_class(
141			cls_str: str,
142			source: object,
143			fork_inst: type) -> type:
144			cls = fork_inst._announced_classes.get(cls_str)
145			if not cls:
146			msg = ('Could not find a suitable type for "{}". Make sure it can be '
147			'imported or that is has been announced.'.format(cls_str))
148			raise UnknownClassError(msg, source, cls_str)
149			return cls
150
151
152			def _get_simple_name(cls: type) -> str:
153			if cls is None:
154			cls = type(cls)
155			cls_name = getattr(cls, '__name__', None)
156			if not cls_name:
157			cls_name = getattr(cls, '_name', None)
158			if not cls_name:
159			cls_name = repr(cls)
160			cls_name = cls_name.split('[')[0] # Remove generic types.
161			cls_name = cls_name.split('.')[-1] # Remove any . caused by repr.
162			cls_name = cls_name.split(r"'>")[0] # Remove any '>.
163			return cls_name
164
165
166			def _get_module(cls: type) -> Optional[str]:
167			builtin_module = str.__class__.__module__
168			module = getattr(cls, '__module__', None)
169			if module and module != builtin_module:
170			return module
171

ramonhagenaars / jsons

jsons._common_impl.get_cls_and_meta() A last analyzed 2022-06-09 19:52 UTC

Complexity

Size

Duplication

Importance

Duplication Side-by-Side

Filter issues like

jsons._common_impl.get_cls_and_meta() A
last analyzed 2022-06-09 19:52 UTC