Esse exemplo é uma mini API em flask que faz requisição ao banco nos EUA e entrega o blob de três imagens em base64.

Requisicao-usando-threads.py

#!/usr/bin/python3
# -*- Coding: utf-8 -*-
from multiprocessing.dummy import Pool as ThreadPool
from flask import Flask, jsonify
from pymongo import MongoClient
import os

app = Flask(__name__)

# Conectio my 
client = MongoClient('mongodb://example:senha@route.com/images',45704)
db = client.images

# API work
@app.route('/')
def main ():
    # Defining threads, 2 registers
    pool = ThreadPool(2)
    # Selecting colletion
    collection = db['blobs']
    #cursor = collection.find({})
    
    def make(x):
        # The values get information by type
        return 'Fuckindata {"buf":"'+str(collection.find_one({"type":x})["data"])+'"}' 

    # Make a loop in cursor, in collection
    blob = pool.map(make,['a','b','c'])
    pool.close()
    pool.join()
    return jsonify(blob)