Getting a weird 'local variable referenced before assignment' error

Here’s the code – it’s a class method.

    def update(self,xxx):
        print("update=" + str(xxx))
        
        str = "{:.2f}".format(xxx)

getting error on the print statement.

NameError: local variable referenced before assignment

I’ve changed xxx name to other random names – same error.

If I comment out the format statement – then no error.

>Solution :

The problem isn’t with the xxx parameter, but with the local str variable.

The intent of the code isn’t entirely clear to me, but if you rename the str variable to something else (foo, for example), it should work:

def update(self, xxx):
    print("update=" + str(xxx))

    foo = "{:.2f}".format(xxx)

By the way, I would caution against using str (and the names of other built-ins like input etc.) as variable names. It makes the code less clear. It also shadows built-ins, causing strange behavior when you try to use said built-ins.