[python] AttributeError: 'str' object has no attribute

I'm pretty new to python programming and I wanted to try my hand at a simple text adventure game, but I've immediately stumbled on a roadblock.

class userInterface:
    def __init__(self, roomID, roomDesc, dirDesc, itemDesc):
        self.roomID = roomID
        self.roomDesc = roomDesc
        self.dirDesc = dirDesc
        self.itemDesc = itemDesc

    def displayRoom(self): #Displays the room description
        print(self.roomDesc)

    def displayDir(self): #Displays available directions
        L1 = self.dirDesc.keys()
        L2 = ""
        for i in L1:
                L2 += str(i) + " "
        print("You can go: " + L2)

    def displayItems(self): #Displays any items of interest
        print("Interesting items: " + str(self.itemDesc))

    def displayAll(self, num): #Displays all of the above
        num.displayRoom()
        num.displayDir()
        num.displayItems()

    def playerMovement(self): #Allows the player to change rooms based on the cardinal directions
        if input( "--> " ) in self.dirDesc.keys():
            letsago = "ID" + str(self.dirDesc.values())
            self.displayAll(letsago)
        else:
            print("Sorry, you can't go there mate.")



ID1 = userInterface(1, "This is a very small and empty room.", {"N": 2}, "There is nothing here.")

ID2 = userInterface(2, "This is another room.", {"W": 3}, ["knife", "butter"])

ID3 = userInterface(3, "This is the third room. GET OVER HERE", {}, ["rocket launcher"])

ID1.displayAll(ID1)
ID1.playerMovement()

That is my code, which for some reason throws that error:

Traceback (most recent call last):
  File "D:/Python34/Text Adventure/framework.py", line 42, in <module>
    ID1.playerMovement()
  File "D:/Python34/Text Adventure/framework.py", line 30, in playerMovement
    self.displayAll(fuckthis)
  File "D:/Python34/Text Adventure/framework.py", line 23, in displayAll
    num.displayRoom()
AttributeError: 'str' object has no attribute 'displayRoom'

I've search on the internet and in python documentation what the hell am I doing wrong here and I have no idea. If I'll put ID2 or ID3 in place of self.displayAll(letsago) it works perfectly, but it's pointless since player has no control over where he wants to go, so I'm guessing there is something wrong with trying to connect ID with the number from the dictionary, but I have no idea what to do and how to fix this.

The problem is in your playerMovement method. You are creating the string name of your room variables (ID1, ID2, ID3):

letsago = "ID" + str(self.dirDesc.values())

However, what you create is just a str. It is not the variable. Plus, I do not think it is doing what you think its doing:

>>>str({'a':1}.values())
'dict_values([1])'

If you REALLY needed to find the variable this way, you could use the eval function:

>>>foo = 'Hello World!'
>>>eval('foo')
'Hello World!'

or the globals function:

class Foo(object):
    def __init__(self):
        super(Foo, self).__init__()
    def test(self, name):
        print(globals()[name])

foo = Foo()
bar = 'Hello World!'
foo.text('bar')

However, instead I would strongly recommend you rethink you class(es). Your userInterface class is essentially a Room. It shouldn't handle player movement. This should be within another class, maybe GameManager or something like that.