如何约束PolyFactory生成的类型？避免Dict中出现datetime字段

方法1：自定义字段生成器过滤datetime #

通过重写TypedDictFactory的get_value方法，自定义值生成逻辑，递归处理嵌套dict时排除datetime类型：

from typing import Any, Type
from polyfactory.factories.typed_dict_factory import TypedDictFactory
from polyfactory.value_generators import generate_random_value
from datetime import datetime

def filter_datetime_value_generator(type_: Type[Any]) -> Any:
    if type_ is dict:
        def build_filtered_dict() -> dict:
            filtered_dict = {}
            for _ in range(3):
                key = generate_random_value(str)
                # 指定允许生成的类型，排除datetime
                value = generate_random_value((int, str, float, list, dict))
                if isinstance(value, dict):
                    value = build_filtered_dict()
                elif isinstance(value, list):
                    value = [generate_random_value((int, str, float, dict)) for _ in range(2)]
                filtered_dict[key] = value
            return filtered_dict
        return build_filtered_dict()
    # 遇到datetime类型时，替换为其他允许的类型
    elif type_ is datetime:
        return generate_random_value(str)
    return generate_random_value(type_)

class FilteredTypedDictFactory(TypedDictFactory):
    @classmethod
    def get_value(cls, type_: Type[Any]) -> Any:
        return filter_datetime_value_generator(type_)

class S(TypedDict):
    d: dict

print(FilteredTypedDictFactory.create_factory(model=S).build())

方法2：用自定义类型别名明确允许的类型 #

即使嵌套结构复杂，也可以定义递归的类型别名，限定dict的取值范围，让PolyFactory仅生成指定类型：

from typing import TypedDict, Union, List, Dict
from polyfactory.factories.typed_dict_factory import TypedDictFactory

# 递归定义允许的类型，完全排除datetime
AllowedValue = Union[int, str, float, List['AllowedValue'], Dict[str, 'AllowedValue']]

class S(TypedDict):
    d: Dict[str, AllowedValue]

print(TypedDictFactory.create_factory(model=S).build())

方法3：全局配置排除datetime类型 #

直接修改PolyFactory的全局配置，禁止生成datetime类型实例：

from polyfactory import configure
from datetime import datetime
from polyfactory.factories.typed_dict_factory import TypedDictFactory
from typing import TypedDict

# 全局排除datetime类型
configure(exclude_types=[datetime])

class S(TypedDict):
    d: dict

print(TypedDictFactory.create_factory(model=S).build())

内容的提问来源于stack exchange，提问作者user24471097