Generateurv2/backend/env/lib/python3.10/site-packages/faker/proxy.py
2022-06-24 17:14:37 +02:00

327 lines
11 KiB
Python

import copy
import functools
import re
from collections import OrderedDict
from random import Random
from typing import Any, Callable, Dict, List, Optional, Pattern, Sequence, Tuple, Union
from .config import DEFAULT_LOCALE
from .exceptions import UniquenessException
from .factory import Factory
from .generator import Generator, Sentinel, random
from .typing import SeedType
from .utils.distribution import choices_distribution
_UNIQUE_ATTEMPTS = 1000
class Faker:
"""Proxy class capable of supporting multiple locales"""
cache_pattern: Pattern = re.compile(r"^_cached_\w*_mapping$")
generator_attrs = [
attr for attr in dir(Generator) if not attr.startswith("__") and attr not in ["seed", "seed_instance", "random"]
]
def __init__(
self,
locale: Optional[Union[str, Sequence[str], Dict[str, Union[int, float]]]] = None,
providers: Optional[List[str]] = None,
generator: Optional[Generator] = None,
includes: Optional[List[str]] = None,
use_weighting: bool = True,
**config: Any,
) -> None:
self._factory_map = OrderedDict()
self._weights = None
self._unique_proxy = UniqueProxy(self)
if isinstance(locale, str):
locales = [locale.replace("-", "_")]
# This guarantees a FIFO ordering of elements in `locales` based on the final
# locale string while discarding duplicates after processing
elif isinstance(locale, (list, tuple, set)):
locales = []
for code in locale:
if not isinstance(code, str):
raise TypeError('The locale "%s" must be a string.' % str(code))
final_locale = code.replace("-", "_")
if final_locale not in locales:
locales.append(final_locale)
elif isinstance(locale, OrderedDict):
assert all(isinstance(v, (int, float)) for v in locale.values())
odict = OrderedDict()
for k, v in locale.items():
key = k.replace("-", "_")
odict[key] = v
locales = list(odict.keys())
self._weights = list(odict.values())
else:
locales = [DEFAULT_LOCALE]
for locale in locales:
self._factory_map[locale] = Factory.create(
locale,
providers,
generator,
includes,
use_weighting=use_weighting,
**config,
)
self._locales = locales
self._factories = list(self._factory_map.values())
def __dir__(self):
attributes = set(super(Faker, self).__dir__())
for factory in self.factories:
attributes |= {attr for attr in dir(factory) if not attr.startswith("_")}
return sorted(attributes)
def __getitem__(self, locale: str) -> Generator:
return self._factory_map[locale.replace("-", "_")]
def __getattribute__(self, attr: str) -> Any:
"""
Handles the "attribute resolution" behavior for declared members of this proxy class
The class method `seed` cannot be called from an instance.
:param attr: attribute name
:return: the appropriate attribute
"""
if attr == "seed":
msg = "Calling `.seed()` on instances is deprecated. " "Use the class method `Faker.seed()` instead."
raise TypeError(msg)
else:
return super().__getattribute__(attr)
def __getattr__(self, attr: str) -> Any:
"""
Handles cache access and proxying behavior
:param attr: attribute name
:return: the appropriate attribute
"""
if len(self._factories) == 1:
return getattr(self._factories[0], attr)
elif attr in self.generator_attrs:
msg = "Proxying calls to `%s` is not implemented in multiple locale mode." % attr
raise NotImplementedError(msg)
elif self.cache_pattern.match(attr):
msg = "Cached attribute `%s` does not exist" % attr
raise AttributeError(msg)
else:
factory = self._select_factory(attr)
return getattr(factory, attr)
def __deepcopy__(self, memodict: Dict = {}) -> "Faker":
cls = self.__class__
result = cls.__new__(cls)
result._locales = copy.deepcopy(self._locales)
result._factories = copy.deepcopy(self._factories)
result._factory_map = copy.deepcopy(self._factory_map)
result._weights = copy.deepcopy(self._weights)
result._unique_proxy = UniqueProxy(self)
result._unique_proxy._seen = {k: {result._unique_proxy._sentinel} for k in self._unique_proxy._seen.keys()}
return result
def __setstate__(self, state: Any) -> None:
self.__dict__.update(state)
@property
def unique(self) -> "UniqueProxy":
return self._unique_proxy
def _select_factory(self, method_name: str) -> Factory:
"""
Returns a random factory that supports the provider method
:param method_name: Name of provider method
:return: A factory that supports the provider method
"""
factories, weights = self._map_provider_method(method_name)
if len(factories) == 0:
msg = f"No generator object has attribute {method_name!r}"
raise AttributeError(msg)
elif len(factories) == 1:
return factories[0]
if Generator._global_seed is not Sentinel:
random.seed(Generator._global_seed) # type: ignore
if weights:
factory = self._select_factory_distribution(factories, weights)
else:
factory = self._select_factory_choice(factories)
return factory
def _select_factory_distribution(self, factories, weights):
return choices_distribution(factories, weights, random, length=1)[0]
def _select_factory_choice(self, factories):
return random.choice(factories)
def _map_provider_method(self, method_name: str) -> Tuple[List[Factory], Optional[List[float]]]:
"""
Creates a 2-tuple of factories and weights for the given provider method name
The first element of the tuple contains a list of compatible factories.
The second element of the tuple contains a list of distribution weights.
:param method_name: Name of provider method
:return: 2-tuple (factories, weights)
"""
# Return cached mapping if it exists for given method
attr = f"_cached_{method_name}_mapping"
if hasattr(self, attr):
return getattr(self, attr)
# Create mapping if it does not exist
if self._weights:
value = [
(factory, weight)
for factory, weight in zip(self.factories, self._weights)
if hasattr(factory, method_name)
]
factories, weights = zip(*value)
mapping = list(factories), list(weights)
else:
value = [factory for factory in self.factories if hasattr(factory, method_name)] # type: ignore
mapping = value, None # type: ignore
# Then cache and return results
setattr(self, attr, mapping)
return mapping
@classmethod
def seed(cls, seed: Optional[SeedType] = None) -> None:
"""
Hashables the shared `random.Random` object across all factories
:param seed: seed value
"""
Generator.seed(seed)
def seed_instance(self, seed: Optional[SeedType] = None) -> None:
"""
Creates and seeds a new `random.Random` object for each factory
:param seed: seed value
"""
for factory in self._factories:
factory.seed_instance(seed)
def seed_locale(self, locale: str, seed: Optional[SeedType] = None) -> None:
"""
Creates and seeds a new `random.Random` object for the factory of the specified locale
:param locale: locale string
:param seed: seed value
"""
self._factory_map[locale.replace("-", "_")].seed_instance(seed)
@property
def random(self) -> Random:
"""
Proxies `random` getter calls
In single locale mode, this will be proxied to the `random` getter
of the only internal `Generator` object. Subclasses will have to
implement desired behavior in multiple locale mode.
"""
if len(self._factories) == 1:
return self._factories[0].random
else:
msg = "Proxying `random` getter calls is not implemented in multiple locale mode."
raise NotImplementedError(msg)
@random.setter
def random(self, value: Random) -> None:
"""
Proxies `random` setter calls
In single locale mode, this will be proxied to the `random` setter
of the only internal `Generator` object. Subclasses will have to
implement desired behavior in multiple locale mode.
"""
if len(self._factories) == 1:
self._factories[0].random = value
else:
msg = "Proxying `random` setter calls is not implemented in multiple locale mode."
raise NotImplementedError(msg)
@property
def locales(self) -> List[str]:
return list(self._locales)
@property
def weights(self) -> Optional[List[Union[int, float]]]:
return self._weights
@property
def factories(self) -> List[Generator]:
return self._factories
def items(self) -> List[Tuple[str, Generator]]:
return list(self._factory_map.items())
class UniqueProxy:
def __init__(self, proxy: Faker):
self._proxy = proxy
self._seen: Dict = {}
self._sentinel = object()
def clear(self) -> None:
self._seen = {}
def __getattr__(self, name: str) -> Any:
obj = getattr(self._proxy, name)
if callable(obj):
return self._wrap(name, obj)
else:
raise TypeError("Accessing non-functions through .unique is not supported.")
def __getstate__(self):
# Copy the object's state from self.__dict__ which contains
# all our instance attributes. Always use the dict.copy()
# method to avoid modifying the original state.
state = self.__dict__.copy()
return state
def __setstate__(self, state):
self.__dict__.update(state)
def _wrap(self, name: str, function: Callable) -> Callable:
@functools.wraps(function)
def wrapper(*args, **kwargs):
key = (name, args, tuple(sorted(kwargs.items())))
generated = self._seen.setdefault(key, {self._sentinel})
# With use of a sentinel value rather than None, we leave
# None open as a valid return value.
retval = self._sentinel
for i in range(_UNIQUE_ATTEMPTS):
if retval not in generated:
break
retval = function(*args, **kwargs)
else:
raise UniquenessException(f"Got duplicated values after {_UNIQUE_ATTEMPTS:,} iterations.")
generated.add(retval)
return retval
return wrapper