json1 = {'Car': {'Brand': 'Audi', 'Nationality': 'Germany', 'Modelname':
    'A6'}, 'Engine': {'cubic capacity': '2967', 'Enginetype': 'V6', 'Fuel':
    'Diesel', 'MaxSpeed': '250'}, 'Colors': {'Carcolor': 'Black',
    'Interiorrcolor': 'white'}}
json2 = {'Car': {'Brand': 'Audi', 'Nationality': 'USA', 'Modelname': 'A6'},
    'Engine': {'cubic capacity': '2995', 'Enginetype': 'V6', 'Fuel':
    'Petrol', 'MaxSpeed': '250'}, 'Colors': {'Carcolor': 'Black',
    'Interiorrcolor': 'Black'}}

def common_dict(d1, d2):
    output = {}
for k in (set(d1) & set(d2)):
    o1, o2 = d1[k], d2[k]
if isinstance(o1, dict) and isinstance(o2, dict):
    pass
Python - Getting the intersection of two Json-Files