data_dict={
            "k1":"v1",
            "k2":"v2",
            "k3":"v3",
            "k4":"v4",
          }
#类型1：
rel={}
print(bool(rel))  #False
for k,v in data_dict.items():
    temp_dict={}
    temp_dict[k]=v
    if temp_dict:
        rel[temp_dict[k]]=temp_dict
print(rel)
'''
{'v1': {'k1': 'v1'}, 'v2': {'k2': 'v2'}, 'v3': {'k3': 'v3'}, 'v4': {'k4': 'v4'}}
'''