The code is as follows

# -*- coding: utf-8 -*-
from datetime import datetime, date
from flask.json import JSONEncoder
class CustomJSONEncoder(JSONEncoder):
def default(self, obj):
if isinstance(obj, datetime):
return obj.strftime('%Y-%m-%d %H:%M:%S')
elif isinstance(obj, date):
return obj.strftime('%Y-%m-%d')
else:
return JSONEncoder.default(self, obj)

Use

from datetime import datetime
from flask import Flask, jsonify
app = Flask(__name__)
# Replace the default json Encoder 
app.json_encoder = CustomJSONEncoder
@app.route('/test')
def test_world():
time = datetime.now()
return jsonify({
'time': time})

effect

{

"time": "2020-09-17 16:31:55"
}

Reference resources
About python： Use Flask Of jsonify when , take datetime.date Keep for ’yyyy-mm-dd’ Format