seperate python flask files into multiple files

Question

I've already read much about it on stack overflow but now I'm struggling with an issue and don't know how to fix it.

My main.py looks like the following:

from flask import Flask, jsonify, request

from flask_pymongo import PyMongo
from bson.objectid import ObjectId
from flask_cors import CORS

app = Flask(__name__)


# connect to LiTags database
app.config["MONGO_URI"] = "mongodb://localhost:27017/LiTags"

mongo = PyMongo(app)

CORS(app)

if __name__ == "__main__":
    app.run(debug=True)

then I seperated some database requests (MongoDB) in another file(requests.py). I know that it's not necessary right now because there are not that much requests right now but there will be more after I fixed this problem.

So this is my requests.py:

from main import app, mongo
from flask import Flask, jsonify, request, Blueprint
from flask_pymongo import PyMongo
from bson.objectid import ObjectId


@app.route("/", methods=["GET"])
def getProjects():
    result = []
    projects = mongo.db.literature

    for field in projects.find():
        result.append(
            {"_id": str(field["_id"]), "project_name": field["project_name"]})

    return jsonify(result)

this is generally my frontend (ReactJS) request to flask:

// get project names from the backend
  getProjects() {
    axios.get(`http://127.0.0.1:5000/`)
      .then(res => {
        this.setState({ projects: res.data });
      })
  }

before I seperated the requests in requests.py from the main.py my program worked but now I get an error in the inspect tool in the browser which says:

"GET http://127.0.0.1:5000/ 404 (NOT FOUND)
Error: Request failed with status code 404
    at createError (createError.js:17)
    at settle (settle.js:19)
    at XMLHttpRequest.handleLoad (xhr.js:63)"

BTW: most people and tutorials/documentations use name `views.py` instead of `requests.py` for file with code which use `@app.route`. — furas, Apr 09 '20 at 16:41
please check: https://stackoverflow.com/questions/11994325/how-to-divide-flask-app-into-multiple-py-files — Yosua, Apr 09 '20 at 16:43
you have to `import requests` in `main.py` - without import it never use code from `requests.py` so it doesn't use code `@app.route("/", methods=["GET"])` and when browser try to connect to `http://127.0.0.1:5000/` then Flask doesn't know what to do. — furas, Apr 09 '20 at 16:43
BTW: you will have problem with `circular import` because in `main.py` you have to import `requests.py` but `requests.py` already imports `main.py`. You would have to create new file ie. `run.py` which imports first from `main.py`, next from `requests.py` and finally it runs `app.run()` — furas, Apr 09 '20 at 16:55

score 1 · Accepted Answer · answered Apr 09 '20 at 17:08

In main.py you would have to import requests.py

from requests import *

because main.py doesn't know that you have code in other file .

But there can be problem with circular imports - main.py has to import requests.py but requests.py aready imports main.py and it makes problem.

You may have to split main in two files:

main.py - which doesn't need code from reuqests so it doesn't have to import it

from flask import Flask, jsonify, request

from flask_pymongo import PyMongo
from bson.objectid import ObjectId
from flask_cors import CORS

app = Flask(__name__)

# connect to LiTags database
app.config["MONGO_URI"] = "mongodb://localhost:27017/LiTags"

mongo = PyMongo(app)

CORS(app)

run.py - which needs code from requests (but requests doesn't import it)

from main import *
#from main import app
from requests import *

#from models import *
#from views import *
#from admin import *    

if __name__ == "__main__":
    app.run(debug=True)

and now you would have to use run.py instead of main.py to start server.

python run.py

BTW: most people and tutorials/documentations use name views.py instead of requests.py for file with code which use @app.route. Eventaully I would use name api.py because these views return JSON data like in many APIs.

seperate python flask files into multiple files

1 Answers1