using an uninitialized global variable throws NameError

Question

This code throws NameError: name 'x' is not defined":

def function():
    global x
    print(x)

function()
print(x)

However, this code works and prints "2" two times:

def function():
    global x
    x = 2
    print(x)

function()
print(x)

My question is, what actually happens at the moment x is declared as global?

Answer 1

You have not defined x, resulting in the errors. Try and make the function have a parameter of x.

def function(x):
    print(x)

Also, when you globalize a variable, its scope is not just within the function, but in every function/class.

• Carden