问题
i have an api and i am trying to store/post a user object using Flask-Pymongo.
but, i get the following error
File "/home/kay/.local/share/virtualenvs/server-iT4jZt3h/lib/python3.7/site-packages/flask/json/i│ nit.py", line 321, in jsonify
│ dumps(data, indent=indent, separators=separators) + '\n', │ File "/home/kay/.local/share/virtualenvs/server-iT4jZt3h/lib/python3.7/site-packages/flask/json/i│ nit.py", line 179, in dumps
│ rv = _json.dumps(obj, **kwargs) │ File "/usr/lib/python3.7/json/init.py", line 238, in dumps
│ **kw).encode(obj) │ File "/usr/lib/python3.7/json/encoder.py", line 201, in encode
│ chunks = list(chunks) │ File "/usr/lib/python3.7/json/encoder.py", line 438, in _iterencode │ o = _default(o) │ File "/home/kay/link/server/src/run.py", line 18, in default
│ return json.JSONEncoder.default(self, o) │ File "/usr/lib/python3.7/json/encoder.py", line 179, in default
│ raise TypeError(f'Object of type {o.class.name} ' │ TypeError: Object of type InsertOneResult is not JSON serializable
app/users/resource.py
from flask_restful import Resource
from flask import jsonify, request
from .repository import UsersRepository
from db import mongo
class UsersResource(Resource):
def __init__(self):
self.repository = UsersRepository()
def get(self):
data = {"Users": "Resource"}
res = data, 200
return res
def post(self):
req = request.get_json()
user = {
"email": req.get("email"),
"password": req.get("password")
}
result = mongo.db.users.insert_one(user)
return jsonify(result)
run.py
from flask import Flask
from app import api_bp
from db import mongo
from bson.objectid import ObjectId
import json
import datetime
import os
class JSONEncoder(json.JSONEncoder):
def default(self, o):
if isinstance(o, ObjectId):
return str(o)
if isinstance(o, set):
return list(o)
if isinstance(o, datetime.datetime):
return str(o)
return json.JSONEncoder.default(self, o)
def create_app(config_filename):
app = Flask(__name__)
app.config.from_object(config_filename)
app.register_blueprint(api_bp, url_prefix='/api')
mongo.init_app(app)
app.json_encoder = JSONEncoder
return app
# def logger():
# def database():
if __name__ == "__main__":
app = create_app("config")
app.run(host='0.0.0.0', port=8080, debug=True)
回答1:
- from bson.objectid import ObjectId
from bson import json_util
- use pymongo json_util bson to handle BSON types
use force=true when getting json input :
- req = request.get_json(force=true)
- use default values when getting dict fields like :
- req.get("email", "")
you can check if fields are empty or not before inserting into mongo.
回答2:
Simple Solution I found from here is
TypeError: ObjectId('') is not JSON serializable
Response -> bson dumps (searlization) -> json loads (deserialization)
Code is as follows :
from bson.json_util import dumps,RELAXED_JSON_OPTIONS
import json
def post(self,name):
dream = {'name':name , 'price' : 12.00 }
dreams.append(dream)
dreamDao.addDream(dream) #MongoDB Call to Insert Data
bs = dumps(dream,json_options=RELAXED_JSON_OPTIONS) #Now dream has Response Which will have ObjectId
return json.loads(bs) , 201
回答3:
The line TypeError: Object of type InsertOneResult is not JSON serializable describes the problem. insert_one() returns an InsertOneResult object, which contains the inserted ID (as @styvane's comment suggested) as well as a flag indicating whether the write was ack'd by the database. Other operations have similar result objects, and none of them are JSON serializable.
A future version of Flask-PyMongo may add helpers to support this, you can follow https://github.com/dcrosta/flask-pymongo/issues/62 to add ideas and suggestions.
回答4:
from flask_pymongo import Pymongo
import json
import pandas as pd
user = pd.DataFrame(user)
mongo.db.users.insert_one({'email':json.loads(user[0].to_json(orient='index')),
'password':json.loads(user[1].to_json(orient='index'))})
This will throw up errors if your objects are already json. If they aren't though, it'll turn them into json and load them all in one go.
回答5:
I believe that following previous suggestion you can find the answers. But I would like to provide another solution that simplifies it.
The solution assumes that pymongo and flask packages are installed:
from flask import Flask
from flask.json import JSONEncoder
from bson import json_util
from . import resources
# define a custom encoder point to the json_util provided by pymongo (or its dependency bson)
class CustomJSONEncoder(JSONEncoder):
def default(self, obj): return json_util.default(obj)
application = Flask(__name__)
application.json_encoder = CustomJSONEncoder
if __name__ == "__main__":
application.run()
回答6:
It seems that what you post to server is not a valid json object. So you should debug what you got.
class UsersResource(Resource):
def post(self):
# debug
print("request.args is {}".format(request.args))
print("request.form is {}".format(request.form))
print("request.data is {}".format(request.data))
req = request.get_json()
user = {
"email": req.get("email"),
"password": req.get("password")
}
result = mongo.db.users.insert_one(user)
return jsonify(result)
来源：https://stackoverflow.com/questions/52569791/flask-pymongo-object-of-type-insertoneresult-is-not-json-serializable