Globals and Functions… and Kivy (Python 2.7.10) (Kivy 1.9.1)

Question

I'm trying to use Kivy to add a GUI to some script. However, the following is stalling me significantly:

class SearchScreen(Screen):
    search_input = ObjectProperty()

    users_dic = {}

    def search_user(self):
        globals()["users_dic"] = GetSessionToken.find_user(
        self.search_input.text, agent_head)

        print globals()['users_dic']

        users = [key for key in users_dic.iterkeys()]

        self.search_results.item_strings = users

        self.search_results.adapter.data[:]
        self.search_results.adapter.data.extend(users)
        self.search_results._trigger_reset_populate()

    class userButton(ListItemButton):
        pass

    def getUserSession(self, user):
        global current_user, user_header, session_token

        current_user = user

        users_dic = globals()['users_dic']

        print users_dic

        try:
            user_header, session_token = GetSessionToken.UserSession(
            users_dic[user], agent_head)
            return self.root.changeScreen("operations")
        except ValueError:
            return self.root.changeScreen("denied")

It produces this error:

 KeyError: 'users_dic'

I do not understand why this is working for "search_user" but not for "getUserSession" . To confirm, "search_user" prints out the dictionary:

{u'user1': u'202703', u'user2': u'202702', u'user3': u'201105'}

I want to be provided with "202703" when I run "getUserSession('user1')". What am I missing about Globals ? What are the differences between the way the functions are handling "users_dic"?

EDIT:

search_user is being called in the Kivy language file as follows:

<SearchScreen@Screen>:
    search_input: search_box
    search_results: search_results_list
    BoxLayout:
        orientation: "vertical"
        BoxLayout
            height: root.height/10
            size_hint_y: None
            TextInput:
                id: search_box
                size_hint_x: 75
            Button:
                text:"Search"
                size_hint_x: 25
                on_press: root.search_user()

getUserSession is being called within the Kivy language file as follows:

<userButton>:
    on_press: main.SearchScreen().getUserSession(self.text)

Answer 1

In search_user you have set a value to Globals["users_dic"] , therefore you were able to access it, when your code reached getUserSession user_dic is not yet defined in Globals .

If you had called search_user prior to calling getUserSession , you should be able to access users_dic as part of the Globals , like shown in this example:

class Foo():
    def test(self):
        globals()['test'] = 'test'
    def post_test(self):
        print globals()['test']

foo = Foo()
foo.test()
foo.post_test()
>>test

Just to be clear, setting users_dic in the class scope doesn't make it part of Globals .

Answer 2

For anybody who may stumble across an issue similar to mine, I worked around the problem by moving the function to be within the root widget, and changing the event to reference this instead.

This means moving the function from being within:

class SearchScreen(Screen):

to being under:

class AgentAppRoot(BoxLayout):

Then changing the event from:

on_press: root.getUserSession(self.text)

to:

on_press: main.SearchScreen().getUserSession(self.text)

I am unsure as to why this has worked, but it has... for now. For anybody in my position I regret I am unable to offer anything further.