dbm.error: need 'c' or 'n' flag to open new db

#coding=utf-8

import shelve

with shelve.open("shelve.ini","w") as f:

    f["k1"] = test_list

    f["k2"] = test_dict

    f["k3"] = s

with shelve.open("shelve.ini","r") as f:

    print(f["k3"])

    print(f["k2"])

    print(f["k1"])

报错

    raise error[]("need 'c' or 'n' flag to open new db")

dbm.error: need 'c' or 'n' flag to open new db

改为如下，加入c参数：

#coding=utf-

import shelve

test_list=[,,,,]

test_dict={"aaa":,"bbb":}

s="xiaoming"

with shelve.open("shelve.ini","wc") as f:

    f["k1"] = test_list

    f["k2"] = test_dict

    f["k3"] = s

with shelve.open("shelve.ini","rc") as k:

    print(k["k3"])

    print(k["k2"])

    print(k["k1"])

输出

xiaoming

{'aaa': , 'bbb': }

[, , , , ]