If i want to update the valve of global variable inside the function than how i can do this

Question

You can take given below example to explain clearly
x=10
def glb(num):
#here I want to update value of x
# if i write x+=20 its shows error why??
l=15
print(num,l,x)
glb(10)

Answer 1

Because x is not defined inside the function.

You can enter:

x = 10
def glb(num):
global x
x += 20
l = 15
print(num, l, x)

Its not usually the best idea, but it'll work. What exactly are you trying to do? the variable num isnt even being used