导入函数中的 Python 3.8 模块重复和应用程序对象范围

Question

I'm confused about import of custom modules. As you can see in the code below, in main I first import all libraries needed by everything AND that I duplicated those imports in my i_setup_functions.py file. Leaving any of them out of either file created errors. Same with duplication of "app = Flask( name )". I really hope that redundancy is not correct and there is some simple way to fix this. All I want to do is include setup for sessions, email, data connection, etc. Only showing sessions here for simplicity sake.

BTW: The entire app worked bug-free until I tried to modularize.

Error message:

RuntimeError: The session is unavailable because no secret key was set. Set the secret_key on the application to something unique and secret.

That error message points to a line in a function in the middle of main.py that tries to create a session.

Thanks for any ideas you all can share!

main.py:

from flask import session
import random
from datetime import datetime, timedelta
from i_setup_functions import setup_sessions

app = Flask(__name__)
# is the following line even necessary in either module?
application = app

setup_sessions()
setup_mail()
setup_logging()
[snip]
# Error here:
​session["id_user"] = id_user

i_setup_functions.py

from flask import session
import random
from datetime import datetime, timedelta
from i_setup_functions import setup_sessions

app = Flask(__name__)
application = app

def setup_sessions():
    random.seed(datetime.now())
    app.config['SECRET_KEY'] = str(random.randint(1, 500)) + "jibber" + str(random.randint(1, 500)) + "jabber"
    app.permanent_session_lifetime = timedelta(days=30)
    return True

Answer 1

You are creating two (or more?) separate apps and setting the SECRET_KEY to the one that isn't serving your application.

To fix this remove all app = Flask(__name__) calls from all modules except main.py . Then, pass the app you create in main.py to all the places you need it.

from flask import session
import random
from datetime import datetime, timedelta
from i_setup_functions import setup_sessions

app = Flask(__name__)

setup_sessions(app)
setup_mail(app)
setup_logging(app)

[snip]

​session["id_user"] = id_user