add dictionarie in json file

[Gribouillis]

You could load the list before appending

with open('testjson_dict.json') as ifh:
    list1 = json.load(ifh)
dict3 = {'e': 3, 'f': 3}
list1.append(dict3)
with open('testjson_dict.json', 'w') as f:
    json.dump(list1, f)