Related to using the global object in flask.

Hello.

I have a question while reading a book called "Flask-based Python Web Programming."

The contents below are part of the book.

"Global objects are efficient at storing and using data that needs to be shared across applications, but multiple simultaneous access to attributes stored on global objects can cause application operational problems."

from flask import g

@resource.after_request
def after_request(response):
    # One example of using a global object.
    pritn g.userid

# Default Auth Check
def authCheck(func):
    @wraps(func)
    def checkFunc(*args, **kwargs):
        g.userid = 'H2'
        return func(*args, **kwargs)
    return checkFunc

@app.route("/")
@authCheck
def main():
    # Another example of using a global object.
    print "hello", g.userid 

Among the above, there is a part called "multiple simultaneous access." Previously, I was using the global object as a user ID. (g.userid)

When processing a request for a session, make sure that any function can obtain and use its ID value...

By the way, are you saying that the contents of the above book should not be used with me? If multiple users' requests come in at the same time, can the ID value change?

Then it's a big problem.

I am currently running a web service with nginx + uwsgi + flask combination.

Please give us advice from masters.

Then have a good day today.