Python local variable defined in an enclosing scope referenced before assignment in multiple functions

Question

I have the following code:

class MyFirstClass:
    
    def myDef(self):
        global x, y
        x = 'some_str'
        y = 0

class MySecondClass:

    def myOtherDef(self):
        for i in range(10):
            y += 1
            if y % 2 == 0:
                y = 0
                x = 'new_str'

However, y += 1 errors with local variable 'y' defined in an enclosing scope on line 4 referenced before assignment

How can I re-assign variable y in the new class?

Answer 1

There are 2 issues with this. The first is that you need to define x and y as members of MyFirstClass, not as globals in a method. You won't be able to access them that way. The second is that you need an instance of MyFirstClass in MySecondClass:

class MyFirstClass:
    x = 'some_str'
    y = 0
        
class MySecondClass:
    myFirstClass = MyFirstClass()
    def myOtherDef(self):
        for i in range(10):
            self.myFirstClass.y += 1
            if self.myFirstClass.y % 2 == 0:
                self.myFirstClass.y = 0
                self.myFirstClass.x = 'new_str'
                print(self.myFirstClass.x)


mySecondClass = MySecondClass()
mySecondClass.myOtherDef()

Output:

new_str
new_str
new_str
new_str
new_str