How to correctly read a file with data types preserved?

Question

Python

There is a data file (0:[2,4,5]), how to read this file to get a dictionary {0:[2,4,5]. Thank you.

Answer 1

You have to write a parser.
Depending on the complexity of the data structure, it can be moderately difficult or very difficult.
For example, does the data always contain a single-level dictionary with numeric keys and values ​​as a list of numbers, like in your example? Or maybe there are options?
For simple cases, you can parse the string manually. For complex ones, you will have to enter a tool for creating parsers like ANTLR.

Answer 2

you do not need to write anything, you need to save the data file in valid JSON.
ex:
{"0": [1,2,3]}
read

import json

with open('some_file.txt') as jfile:
    data = json.load(jfile)
    
data
{'0': [2, 4, 5]}
data['0']
[2, 4, 5]
data['0'][0]
2
type(data['0'][0])
<class 'int'>

Answer 3

If the structure is always something like this, then you can use ast

from ast import literal_eval

s = "0:[2,4,5]"
data = literal_eval(f"{{{s}}}")
print(data)
# {0: [2, 4, 5]}