有没有办法在文本周围插入大括号以使其成为字符串格式的字典？

问：

在我的 python 程序中，我有一个添加到文本文件中的键和值列表，我需要能够提取此字符串列表并将其转换为字典。

例如：

    counter = 0
    add = str(counter)
    counterDict = UserID + ": " + add + ", "
    counter = counter + 1

#This should make counterDict look like: ""Smi39119": 0, "Joh38719": 1, " etc.

    f = open("Dictionaries.txt","a")
    f.write(counterDict)
    f.close()

#Then I would like to be able to open the file and turn that string into a dictionary

    f = open("Dictionaries.txt","r")
    string = f.read()

#This way 'string' should still be a string, but look like this: "{"Smi39119": 0, "Joh38719": 1, }"

我不知道这是否可行，但如果可行，将不胜感激所有解决方案。