python - 将字典写入文本文件？

Question

我有一本字典，正在尝试将其写入文件。

exDict = {1:1, 2:2, 3:3}
with open('file.txt', 'r') as file:
    file.write(exDict)

然后我遇到了错误

file.write(exDict)
TypeError: must be str, not dict

所以我修复了这个错误，但又出现了另一个错误

exDict = {111:111, 222:222}
with open('file.txt', 'r') as file:
    file.write(str(exDict))

错误:

file.write(str(exDict))
io.UnsupportedOperation: not writable

如何解决这个问题？

Answer 1

首先，您以读取模式打开文件并尝试写入其中。 咨询-IO modes python

其次，您只能将字符串或字节写入文件。如果要编写字典对象，则需要将其转换为字符串或序列化。

import json

# as requested in comment
exDict = {'exDict': exDict}

with open('file.txt', 'w') as file:
     file.write(json.dumps(exDict)) # use `json.loads` to do the reverse

如果是序列化

import cPickle as pickle

with open('file.txt', 'w') as file:
     file.write(pickle.dumps(exDict)) # use `pickle.loads` to do the reverse

对于 python 3.x pickle 包导入会有所不同

import _pickle as pickle