python中的搁置模块无法正常工作:"db type无法确定"

Question

我试图在Python中创建一个简单的密码存储程序,它看起来很简单,所以我想知道我是否使用搁置错误.

我有主.py文件:

import shelve

passwords = shelve.open('./passwords_dict.py')

choice = raw_input("Add password (a) or choose site (c)?")

if choice[0] == 'a':
    site_key = raw_input("Add for which site? ").lower()
    userpass = raw_input("Add any info such as username, email, or passwords: ")

    passwords[site_key] = userpass

else:
    site = raw_input("Which site? ").lower()
    if site in passwords:
        print "Info for " + site + ": " + passwords[site]
    else:
        print site, "doesn't seem to exist!"

print "Done!"

passwords.close()

而另一个文件passwords_dict.py只是一个空字典.

但是当我尝试运行该程序时,我收到此错误:

Traceback (most recent call last):
File "passwords.py", line 3, in <module>
passwords = shelve.open('passwords_dict.py')
File "/usr/lib/python2.7/shelve.py", line 239, in open
return DbfilenameShelf(filename, flag, protocol, writeback)
File "/usr/lib/python2.7/shelve.py", line 223, in __init__
Shelf.__init__(self, anydbm.open(filename, flag), protocol, writeback)
File "/usr/lib/python2.7/anydbm.py", line 82, in open
raise error, "db type could not be determined"
anydbm.error: db type could not be determined

当我尝试使用anydbm时,我收到此错误:

Traceback (most recent call last):
File "passwords.py", line 3, in <module>
passwords = anydbm.open('passwords_dict.py')
File "/usr/lib/python2.7/anydbm.py", line 82, in open
raise error, "db type could not be determined"
anydbm.error: db type could not be determined

当我尝试使用dbm时,我收到此错误:

Traceback (most recent call last):
File "passwords.py", line 3, in <module>
passwords = dbm.open('./passwords_dict.py')
dbm.error: (2, 'No such file or directory')

我究竟做错了什么？是否存在另一种存储字典的方法,并且仍然能够使用用户输入(而不是整个字典,我认为这是pickle所做的)提取密钥？

Answer 1

我认为你误解了搁架模块是如何工作的.它会打开一个数据库文件.当您尝试打开包含Python脚本的现有文件时,它会尝试检测该文件包含的数据库类型(因为shelve支持多个后端数据库).

我认为你需要这样的东西:

import os
import shelve

curdir = os.path.dirname(__file__)
passwords = shelve.open(os.path.join(curdir, 'password_db'))

这将在与脚本相同的目录中创建一个新文件,password_db.<db>其中<db>是特定于实现的数据库文件扩展名.