How to get a Mock to return a dictionary?

I have read the documents regarding this specific issue, however, I have been unable to actually get it to work in my tests.

Here is the unit-test, using py.test: (input is an instance of InputManager )

def test_invalid_menu_glitch_raises_exception(self, input):
    ''' Test that exception is raised if non-encounter is glitched. '''
    def getitem(name):
        return mydict[name]

    position = 1
    table = Mock()
    mydict = {'step':1, 'input':None, 'enc':False}

    table.getStep.return_value = mydict
    table.__getitem__ = Mock(side_effect=getitem)

    with pytest.raises(IndexError) as indexerr:
        input.glitch(table, position)
    assert 'Cannot Glitch a non-encounter.' in indexerr.value

And the code that I want to test is (specifically glitch() and implicitly setInput():

class InputManager(object):
    ''' Responsible for managing user input. '''
    def __init__(self):
        pass

    def setInput(self, table, position, input):
        ''' Edits the input in table at table[position]. '''
        table.setInput(position, 'G')

    def getStep(self, table, position):
        ''' Returns the step at position. '''
        return table.getStep(position)

    def glitch(self, table, position):
        step_to_glitch = self.getStep(table, position)

        if not step_to_glitch['enc']:
            raise IndexError('Cannot Glitch a non-encounter.')
        self.setInput(table, position, input)

And the error is:

   def test_validate_menu_glitch(self, input):
            ''' Test that menu glitch accepts a valid G input. '''
            table = Mock()
            position = 1
            i = 'G'
>           input.glitch(table(), position)

test_input_manager.py:25: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <input_manager.InputManager object at 0x10a0d3dd0>
table = <Mock name='mock()' id='4463606800'>, position = 1

    def glitch(self, table, position):
            step_to_glitch = self.getStep(table, position)
>           if not step_to_glitch['enc']:
E           TypeError: 'Mock' object has no attribute '__getitem__'

input_manager.py:17: TypeError