datetime.datetime' object is not callable python-CodePudding

I am currently working on an API which is using FastAPI, it is mainly used for adding sensor data into my mongodb database. I also want to add a timestamp (for CET) which is automatically written into the mongodb database with the sensor data.

class DataModel(BaseModel):
    id: PyObjectId = Field(default_factory=PyObjectId, alias="_id")
    loc: str
    sensor: str
    temp: float
    humi: float
    press: float
    power: float
    timestamp: datetime = Field(default_factory=(datetime.utcnow() timedelta(hours=1)))

    class Config:
        allow_population_by_field_name = True
        arbitrary_types_allowed = True
        json_encoders = {ObjectId: str}

Everything is working fine except the timestamp. This error occurs:

{
    "detail": [
        {
            "loc": [
                "body"
            ],
            "msg": "'datetime.datetime' object is not callable",
            "type": "type_error"
        }
    ]
}

I hope you have an idea what the possible problem could be.

    {
        "_id": "637b80a052feee6809711f2c",
        "loc": "Mödling",
        "sensor": "BME680",
        "temp": 5.0,
        "humi": 60.0,
        "press": 1000.0,
        "timestamp": "2022-11-21T13:44:00.371512"
    },

This is the output when im only using datetime.utcnow without the brackets and without the timedelta. When I am using datetime.utcnow() without the timedelta the same problem occurs.

CodePudding user response：

default_factory should be a function, and you are giving a datetime.datetime type

Do a lambda function:

timestamp: datetime = Field(default_factory= lambda : (datetime.utcnow() timedelta(hours=1)))