PYTHON 'Unicode' objet ne prend pas en charge l'élément de détachement

Besoin d'un peu d'aide s'il vous plaît avec cette erreur :

TypeError: "unicode" objet ne prend pas en charge l'élément d'assignation

Ligne : menuDic[str(menu.id)]['menuDishes'][str(d.plat.dishType.nom)]['dishTypeName'][str(d.plat.id)] = {}

def getDishOfTheWeek():
menuDic = Ddict(dict)
for menu in Menus.select().where(state = True):
menuDic[str(menu.id)]={}
menuDic[str(menu.id)]['menuId']=menu.id
menuDic[str(menu.id)]['menuName']=menu.name
menuDic[str(menu.id)]['menuCountry']=menu.country.name
menuDic[str(menu.id)]['menuDishes']={}
for d in DishMenuRels.select().where(menu = menu.id).join(Dishes).join(DishTypes).order_by('name')
menuDic[str(menu.id)]['menuDishes'][str(d.dish.dishType.name)] = {}
menuDic[str(menu.id)]['menuDishes'][str(d.dish.dishType.name)]['dishTypeName'] = d.dish.dishType.name
menuDic[str(menu.id)]['menuDishes'][str(d.dish.dishType.name)]['dishTypeName'][str(d.dish.id)] = {}
menuDic[str(menu.id)]['menuDishes'][str(d.dish.dishType.name)]['dishTypeName'][str(d.dish.id)]['dishId'] = d.dish.id
menuDic[str(menu.id)]['menuDishes'][str(d.dish.dishType.name)]['dishTypeName'][str(d.dish.id)]['dishState'] = d.dish.name
menuDic[str(menu.id)]['menuDishes'][str(d.dish.dishType.name)]['dishTypeName'][str(d.dish.id)]['dishType'] = d.dish.price
menuDic[str(menu.id)]['menuDishes'][str(d.dish.dishType.name)]['dishTypeName'][str(d.dish.id)]['dishName'] = d.dish.country.name
print json.dumps(menuDic, indent=5, sort_keys=True)

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