如何在Python中将字典保存到文件（替代pickle）？

Question

已回答 最后我还是选择了用pickle。

好吧，在我问的另一个问题中，有人建议我用pickle把字典保存到文件里。

我想保存到文件里的字典是

members = {'Starspy' : 'SHSN4N', 'Test' : 'Test1'}

当pickle把它保存到文件时... 这个是保存的格式

(dp0
S'Test'
p1
S'Test1'
p2
sS'Test2'
p3
S'Test2'
p4
sS'Starspy'
p5
S'SHSN4N'
p6
s.

你能给我一个其他的方法来把字符串保存到文件里吗？

我希望保存的格式是这样的

members = {'Starspy' : 'SHSN4N', 'Test' : 'Test1'}

完整代码：

import sys
import shutil
import os
import pickle

tmp = os.path.isfile("members-tmp.pkl")
if tmp == True:
    os.remove("members-tmp.pkl")
shutil.copyfile("members.pkl", "members-tmp.pkl")

pkl_file = open('members-tmp.pkl', 'rb')
members = pickle.load(pkl_file)
pkl_file.close()

def show_menu():
    os.system("clear")
    print "\n","*" * 12, "MENU", "*" * 12
    print "1. List members"
    print "2. Add member"
    print "3. Delete member"
    print "99. Save"
    print "0. Abort"
    print "*" * 28, "\n"
    return input("Please make a selection: ")

def show_members(members):
    os.system("clear")
    print "\nNames", "     ", "Code"
    for keys in members.keys():
        print keys, " - ", members[keys]

def add_member(members):
    os.system("clear")
    name = raw_input("Please enter name: ")
    code = raw_input("Please enter code: ")
    members[name] = code
    output = open('members-tmp.pkl', 'wb')
    pickle.dump(members, output)
    output.close()
    return members


#with open("foo.txt", "a") as f:
#     f.write("new line\n")

running = 1

while running:
    selection = show_menu()
    if selection == 1:
        show_members(members)
        print "\n> " ,raw_input("Press enter to continue")
    elif selection == 2:
        members == add_member(members)
        print members
        print "\n> " ,raw_input("Press enter to continue")
    elif selection == 99:
        os.system("clear")
        shutil.copyfile("members-tmp.pkl", "members.pkl")
        print "Save Completed"
        print "\n> " ,raw_input("Press enter to continue")

    elif selection == 0:
        os.remove("members-tmp.pkl")
        sys.exit("Program Aborted")
    else:
        os.system("clear")
        print "That is not a valid option!"
        print "\n> " ,raw_input("Press enter to continue")

Answer 1

YAML格式（通过pyyaml库）可能是一个不错的选择：

http://en.wikipedia.org/wiki/Yaml

http://pypi.python.org/pypi/PyYAML

Answer 2

当然，可以把它保存为CSV格式：

import csv
w = csv.writer(open("output.csv", "w"))
for key, val in dict.items():
    w.writerow([key, val])

然后读取它的方法是：

import csv
dict = {}
for key, val in csv.reader(open("input.csv")):
    dict[key] = val

另一种选择是使用json格式（如果你用的是2.6及以上版本，可以直接用json，如果是2.5及以下版本，就需要安装simplejson）：

>>> import json
>>> dict = {"hello": "world"}
>>> json.dumps(dict)
'{"hello": "world"}'

Answer 3

现在最常用的序列化格式是JSON，它被广泛支持，并且能够很清晰地表示像字典这样的简单数据结构。

>>> members = {'Starspy' : 'SHSN4N', 'Test' : 'Test1'}
>>> json.dumps(members)
'{"Test": "Test1", "Starspy": "SHSN4N"}'
>>> json.loads(json.dumps(members))
{u'Test': u'Test1', u'Starspy': u'SHSN4N'}