How to set a global variable

You have to declare your var outside your functions and everytime you want to use it inside a function you need to specify the global varName. As i see your global var name at declaration is Kategory and after you use Kategorie.

Python wants to make sure that you really know that you are using global variables by explicitly requiring the global keyword.

To use a global variable within a function you have to explicitly delcare you are using it.

Here a small example:

myGlobalVar= 0 def set_globvar(): global myGlobalVar # Needed to modify global copy of globvar myGlobalVar = 5 def print_globvar(): print myGlobalVar # No need for global declaration to read value of myGlobalVar set_globvar() print_globvar() # Prints 5 

in your case I see that you declare that you want to access global Kategorie but you do not declare access to global Kategory. I do not know if this is a simple typo or if they are 2 different variable. In any case you need to write global yourGlobalVariable

Are there really any globals in python? Yes there is a global keyword that allows you to access varibles in file scope. Another way of accessing the variable is to use the import statement. Lets say you have a file named file.py. In order to write to the variable you could. You could access another files variables just as easy.

import file anyVariable = 42 # ... def aFunc(): file.anyVarible = file.anyVarible + 1