数据类：如何使用 asdict() 忽略 None 值？

@dataclass
class Car:
    brand: str
    color: str

如何获得忽略 None 值的字典？就像是：

>>> car = Car(brand="Audi", color=None)
>>> asdict(car, some_option_to_ignore_none_values=True)
> {'brand': 'Audi'}

所有答案都很好，但对我来说它们太冗长了。这是一行：

# dc is dataclass
# d is dict out
d = asdict(dc, dict_factory=lambda x: {k: v for (k, v) in x if v is not None})

展示：

from typing import Optional, Tuple
from dataclasses import asdict, dataclass

@dataclass
class Space:
    size: Optional[int] = None
    dtype: Optional[str] = None
    shape: Optional[Tuple[int]] = None

s1 = Space(size=2)
s1_dict = asdict(s1, dict_factory=lambda x: {k: v for (k, v) in x if v is not None})
print(s1_dict)
# {"size": 2}

s2 = Space(dtype='int', shape=(2, 5))
s2_dict = asdict(s2, dict_factory=lambda x: {k: v for (k, v) in x if v is not None})
print(s2_dict)
# {"dtype": "int", "shape": (2, 5)}