Raspi read out a slider value

First of all: A warm hello to everyone. Great job … to the guy(s) have done Blynk, thx.
Google was not my friend in finding a way, to read out the value from a slider in Python, i am sure its so easy, but I am to stupid to find out:

def slider(value):
    global value1
    value1= "".join(value)[0])
print (value1)

printing the value1 iside the funktion: no problem.
but outside: I am to old - to stupid - not experienced enough… you choose.
Would someone be so kind to help? I know it is not a exact Blynk issue… in the german python community so far, nothing helped.

THX a lot.

Raspi 3b - Python3 - Iphone - local server -

I’m still searching for a solution… how to get that slider value outside the Funktion?
(Just in case you speak german: thread in the german python forum)

Any suggestion is highly welcome.
Cheers Stefan