从python中的文本文件初始化字典

Question

I have a complex hierarchical python dictionary like this

      dict = {
               "key1":{"key11":{"a"},"key12":{"b"}},
               "key2":{"key21":{"c"},"key22":{"d"}},
               "key3":{"key31":{"e"},"key32":{"f"}}
             }

      print dict["key2"]["key21"]

The output of this code snippet is "c", so the hierarchical dictionary is interpreted correctly. Now, instead of hard code this hierarchical dictionary in code, I want to read it from a file and assign it to a dictionary object. That's to say, I will create a dict.txt file with the following content:

             {
               "key1":{"key11":{"a"},"key12":{"b"}},
               "key2":{"key21":{"c"},"key22":{"d"}},
               "key3":{"key31":{"e"},"key32":{"f"}}
             }

Of course, I will then run to read the stream of the file

            stream = open("dict.txt", "r")

Then, is there any convenient method in python that allows me to easily assign the content in the stream to a dictionary object dict (not as string)?

Answer 1

我建议您将整个dict = {...}放入文本文件中，将文件命名为something.py ，然后import something并将其直接用作something.dict 。

Answer 2

If you're sure it's in that exact format, that is valid JSON, so you can use json.load(f) to load and parse it.

JSON is much pickier than Python though (eg it chokes on trailing commas, and doesn't accept single quotes), so you might need to use ast.literal_eval .

Answer 3

You could do:

import ast
d = ast.literal_eval(stream.read())

But your data is not just a nested dict, rather it has sets as values (at least if one interprets it as Python syntax), which ast.literal_eval can't handle.

From what I understand, that is not a valid JSON for the same reason.