我正在尝试创建嵌套数据类：
```python
from dataclasses import dataclass, field
import datetime
from typing import List
@dataclass
class LineItem:
    displayName: str
    compareAtPrice: float
    discountedPrice: float
    pricing: str = field(init=False)
    def __post_init__(self):
        self.pricing = (
            "regular" if self.compareAtPrice == self.discountedPrice else "on sale"
        )
@dataclass
class Order:
    createdAt: datetime
    lineItems: List[LineItem]
    def __post_init__(self):
        for l in self.lineItems:
            LineItem(**l)
data = {
    "createdAt": datetime.datetime.now(),
    "lineItems": [
        {
            "displayName": "lineitem 1",
            "compareAtPrice": 28.1,
            "discountedPrice": 28.1,
        },
        {
            "displayName": "lineitem 2",
            "compareAtPrice": 88.1,
            "discountedPrice": 78.1,
        },
    ],
}
print(Order(**data))

Order(createdAt=datetime.datetime(2023, 3, 9, 17, 18, 40, 136535), lineItems=[{'displayName': 'lineitem 1', 'compareAtPrice': 28.1, 'discountedPrice': 28.1}, {'displayName': 'lineitem 2', 'compareAtPrice': 88.1, 'discountedPrice': 78.1}])

<details>
<summary>英文:</summary>
I&#39;m trying to create nested data classes:

def __post_init__(self):
    self.pricing = (
        "regular" if self.compareAtPrice == self.discountedPrice else "on sale"
    )

def __post_init__(self):
    for l in self.lineItems:
        LineItem(**l)

The output is missing the `pricing` field which should be populated by `__post_init__` in `class LineItem`  :

What am I doing wrong here?
</details>
# 答案1
**得分**: 4
你可以在你的 **Order** 类中做一个小改变，如下所示，
```python
@dataclass
class Order:
    createdAt: datetime
    lineItems: List[LineItem>
    def __post_init__(self):
        self.lineItems = [LineItem(**l) for l in self.lineItems]