| from types import MappingProxyType |
| from array import array |
| from frozendict import frozendict |
| from collections.abc import MutableMapping, MutableSequence, MutableSet |
| from enum import Enum |
|
|
| |
|
|
| |
| if not issubclass(array, MutableSequence): |
| |
| MutableSequence.register(array) |
|
|
|
|
| def isIterableNotString(o): |
| from collections import abc |
| |
| return ( |
| isinstance(o, abc.Iterable) and |
| not isinstance(o, memoryview) and |
| not hasattr(o, "isalpha") |
| ) |
|
|
|
|
| def getItems(o): |
| from collections import abc |
| |
| if not isinstance(o, abc.Iterable): |
| raise TypeError("object must be an iterable") |
| |
| if isinstance(o, abc.Mapping): |
| return dict.items |
| |
| return enumerate |
|
|
|
|
| def nil(x): |
| return x |
|
|
|
|
| _freeze_conversion_map = frozendict({ |
| MutableMapping: frozendict, |
| bytearray: bytes, |
| MutableSequence: tuple, |
| MutableSet: frozenset, |
| Enum: nil, |
| }) |
|
|
| _freeze_conversion_map_custom = {} |
|
|
|
|
| class FreezeError(Exception): |
| pass |
|
|
|
|
| class FreezeWarning(UserWarning): |
| pass |
|
|
|
|
| def register(to_convert, converter, *, inverse = False): |
| r""" |
| Adds a `converter` for a type `to_convert`. `converter` |
| must be callable. The new converter will be used by `deepfreeze()` |
| and has precedence over any previous converter. |
| |
| If `to_covert` has already a converter, a FreezeWarning is raised. |
| |
| If `inverse` is True, the conversion is considered from an immutable |
| type to a mutable one. This make it possible to convert mutable |
| objects nested in the registered immutable one. |
| """ |
| |
| if not issubclass(type(to_convert), type): |
| raise ValueError( |
| f"`to_convert` parameter must be a type, {to_convert} found" |
| ) |
| |
| try: |
| converter.__call__ |
| except AttributeError: |
| raise ValueError( |
| f"`converter` parameter must be a callable, {converter}" + |
| "found" |
| ) |
| |
| if inverse: |
| freeze_conversion_map = getFreezeConversionInverseMap() |
| else: |
| freeze_conversion_map = getFreezeConversionMap() |
| |
| if to_convert in freeze_conversion_map: |
| import warnings |
| |
| warnings.warn( |
| f"{to_convert.__name__} is already in the conversion map", |
| FreezeWarning |
| ) |
| |
| if inverse: |
| freeze_conversion_map = _freeze_conversion_inverse_map_custom |
| else: |
| freeze_conversion_map = _freeze_conversion_map_custom |
| |
| freeze_conversion_map[to_convert] = converter |
|
|
|
|
| def unregister(type, inverse = False): |
| r""" |
| Unregister a type from custom conversion. If `inverse` is `True`, |
| the unregistered conversion is an inverse conversion |
| (see `register()`). |
| """ |
| |
| if inverse: |
| freeze_conversion_map = _freeze_conversion_inverse_map_custom |
| else: |
| freeze_conversion_map = _freeze_conversion_map_custom |
| |
| try: |
| del freeze_conversion_map[type] |
| except KeyError: |
| raise FreezeError(f"{type.__name__} is not registered") |
|
|
|
|
| def getFreezeConversionMap(): |
| return _freeze_conversion_map | _freeze_conversion_map_custom |
|
|
|
|
| _freeze_conversion_inverse_map = frozendict({ |
| frozendict: dict, |
| MappingProxyType: dict, |
| tuple: list, |
| }) |
|
|
| _freeze_conversion_inverse_map_custom = {} |
|
|
|
|
| def getFreezeConversionInverseMap(): |
| return ( |
| _freeze_conversion_inverse_map | |
| _freeze_conversion_inverse_map_custom |
| ) |
|
|
|
|
| _freeze_types = ( |
| [x for x in _freeze_conversion_map] + |
| [x for x in _freeze_conversion_inverse_map] |
| ) |
|
|
|
|
| def getFreezeTypes(): |
| return (tuple( |
| _freeze_types + |
| [x for x in _freeze_conversion_map_custom] + |
| [x for x in _freeze_conversion_inverse_map_custom] |
| )) |
|
|
|
|
| _freeze_types_plain = (MutableSet, bytearray, array) |
|
|
|
|
| def deepfreeze( |
| o, |
| custom_converters = None, |
| custom_inverse_converters = None |
| ): |
| r""" |
| Converts the object and all the objects nested in it in its |
| immutable counterparts. |
| |
| The conversion map is in getFreezeConversionMap(). |
| |
| You can register a new conversion using `register()` You can also |
| pass a map of custom converters with `custom_converters` and a map |
| of custom inverse converters with `custom_inverse_converters`, |
| without using `register()`. |
| |
| By default, if the type is not registered and has a `__dict__` |
| attribute, it's converted to the `frozendict` of that `__dict__`. |
| |
| This function assumes that hashable == immutable (that is not |
| always true). |
| |
| This function uses recursion, with all the limits of recursions in |
| Python. |
| |
| Where is a good old tail call when you need it? |
| """ |
| |
| from frozendict import frozendict |
| |
| if custom_converters is None: |
| custom_converters = frozendict() |
| |
| if custom_inverse_converters is None: |
| custom_inverse_converters = frozendict() |
| |
| for type_i, converter in custom_converters.items(): |
| if not issubclass(type(type_i), type): |
| raise ValueError( |
| f"{type_i} in `custom_converters` parameter is not a " + |
| "type" |
| ) |
| |
| try: |
| converter.__call__ |
| except AttributeError: |
| raise ValueError( |
| f"converter for {type_i} in `custom_converters` " + |
| "parameter is not a callable" |
| ) |
| |
| for type_i, converter in custom_inverse_converters.items(): |
| if not issubclass(type(type_i), type): |
| raise ValueError( |
| f"{type_i} in `custom_inverse_converters` parameter " + |
| "is not a type" |
| ) |
| |
| try: |
| converter.__call__ |
| except AttributeError: |
| raise ValueError( |
| f"converter for {type_i} in " + |
| "`custom_inverse_converters`parameter is not a callable" |
| ) |
| |
| type_o = type(o) |
| |
| freeze_types = tuple(custom_converters.keys()) + getFreezeTypes() |
| |
| base_type_o = None |
| |
| for freeze_type in freeze_types: |
| if isinstance(o, freeze_type): |
| base_type_o = freeze_type |
| break |
| |
| if base_type_o is None: |
| |
| |
| try: |
| o.__dict__ |
| except AttributeError: |
| pass |
| else: |
| return frozendict(o.__dict__) |
| |
| try: |
| hash(o) |
| except TypeError: |
| pass |
| else: |
| |
| |
| return o |
| |
| supported_types = ", ".join((x.__name__ for x in freeze_types)) |
| |
| err = ( |
| f"type {type_o} is not hashable or is not equal or a " + |
| f"subclass of the supported types: {supported_types}" |
| ) |
| |
| raise TypeError(err) |
| |
| freeze_conversion_map = getFreezeConversionMap() |
| |
| freeze_conversion_map = freeze_conversion_map | custom_converters |
| |
| if base_type_o in _freeze_types_plain: |
| return freeze_conversion_map[base_type_o](o) |
| |
| if not isIterableNotString(o): |
| return freeze_conversion_map[base_type_o](o) |
| |
| freeze_conversion_inverse_map = getFreezeConversionInverseMap() |
| |
| freeze_conversion_inverse_map = ( |
| freeze_conversion_inverse_map | |
| custom_inverse_converters |
| ) |
| |
| frozen_type = base_type_o in freeze_conversion_inverse_map |
| |
| if frozen_type: |
| o = freeze_conversion_inverse_map[base_type_o](o) |
| |
| from copy import copy |
| |
| o_copy = copy(o) |
| |
| for k, v in getItems(o_copy)(o_copy): |
| o_copy[k] = deepfreeze( |
| v, |
| custom_converters = custom_converters, |
| custom_inverse_converters = custom_inverse_converters |
| ) |
| |
| try: |
| freeze = freeze_conversion_map[base_type_o] |
| except KeyError: |
| if frozen_type: |
| freeze = type_o |
| else: |
| raise |
| |
| return freeze(o_copy) |
|
|
|
|
| __all__ = ( |
| deepfreeze.__name__, |
| register.__name__, |
| unregister.__name__, |
| getFreezeConversionMap.__name__, |
| getFreezeConversionInverseMap.__name__, |
| FreezeError.__name__, |
| FreezeWarning.__name__, |
| ) |
|
|
| del MappingProxyType |
| del array |
| del frozendict |
| del MutableMapping |
| del MutableSequence |
| del MutableSet |
| del Enum |
|
|