Scene description

After the MongoDB database is used to insert data, an error is reported when the flash restful interface is used to return data:

TypeError: Object of type ObjectId is not JSON serializable

Cause analysis

The reason for this problem is that when data is written to MongoDB, even if you do not specify a _id field, a field will be automatically generated for each piece of data _id, for example:

{
    "_id" : ObjectId("6180af3ef261f0827ea248d6"),
    "省份名称" : "澳门",
    "省份链接" : "https://www.gongkaoleida.com/area/3509",
    "省份代号" : "3509"
}

This field is of ObjectId type and cannot be returned using JSON serialization, so an error will be reported

Solution:

Since _id field cannot be converted and has no effect on our actual data. Then pop it up after inserting the data. An example is as follows:

self.db.filter_result.insert_one(item)
item.pop('_id')

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