Variable scope

variable

def F():
	print(x)
def G():
	x=2
	F()
x=1
G()
 
#printed output is 1 not 2

this is because when python runs the function F(), it does not have any local variable named x so it automatically uses the global variable

def F(x):
	print(x)
def G():
    x=2
    F(x)
x=1
G()

this prints 2 because now x is a local variable for F()

Unless we define a variable beforehand, we cant directly use it inside our code. for instance

def G():
	x+=2

gives an error. we can only do this by using the global keyword