如何连接 python 中的模块？

Question

Starting to do some more advanced processes in flask and I'm having a hard time figuring out how to import my error handling file. Code snipets from init and errors. What's wrong?

I cant get the errors module to load. I've tried doing from errors import *, I get an import error, tried moving it out of the factory still get errors. Tried from errors import *, tried import errors. All fail to some degree. Seems to me I'm missing something simple as a comma or something.

here's some code

first file - init

from flask import Flask, render_template

def create_app():
    # Instantiate App
    app = Flask(__name__)

    with app.app_context():
        # Import Blueprints
        from .foodtracker.routes import foodtracker
        from .fitness.routes import fitness
        from .bio.routes import bio
        from .home.routes import home

        # Import models, and error handler
        from . import errors

        # Register Blue Prints
        app.register_blueprint(foodtracker)
        app.register_blueprint(fitness)
        app.register_blueprint(bio)
        app.register_blueprint(home)

        return app

and errors.py

from flask import render_template
from . import app

@app.errorhandler(404)
def pagenotfound(error):
    return render_template('/errors/404.html'), 404

directory structure

/fitlife
   /fitlife
      /bio
      /home
      /fitness
      /foodtracker
   __init__.py
   errors.py
   models.py

Answer 1

You have circular imports. Meaning, the app file tries to import the errors file and the errors file tries to import the app file. The correct way to handle this would be to 'dumb down' the errors.py file, meaning making it only contain the errors themselves without using the decorator to register them. Then, the errors.py file will not need to import app . The registration can be done using app.register_error_handler from the higher-level file, instead.