Which file type can I use for importing data directly into a dictionary; in C#?

Question

I want to store some privacy info that is usually in my code to a local file on my pc, to make sure it won't be committed to version control. I want to read this file in my code into a dictionary directly.

Which file type is works to do this with? I thought about xlsx/csv or json, but I am not sure which is best for reading into a dictionary right away. By the way, I know how to read files with (for example) File.ReadAllText and stuff. It is just that this plain text does not compile easily to a dictionary. I am still free to choose any saving format I want, but here is an example of data

username1 - marja1
password1 - fakepassword
username2 - marja2
password2 - fake

Curious to any suggestions.

Answer 1

There are lots of options, each with their own pros and cons. Any standard format will be easy to deserialize from with a third-party library, so that doesn't differentiate them. But here's a comparison of what your file might look like with each.

Simple Dictionary

Simple key-value pairs. XML wouldn't really work to directly translate a dictionary this way.

INI File

username1 = password1
username2 = password2

JSON

{
  "username1":"password1",
  "username2":"password2",
}

YAML

username1: password1
username2: password2

Object-like

You may want a more advanced model, deserializable into something like the following C# types:

record FileContents(IEnumerable<UserCredential> Credentials);
record UserCredential(string UserName, string Password);

JSON

{
  "credentials": [
    {
      "username": "username1",
      "password": "password1"
    },
    {
      "username": "username2",
      "password": "password2"
    }
  ]
}

YAML

credentials:
- username: username1
  password: password1
- username: username2
  password: password2

XML

<Credentials>
  <User Username="username1" Password="password1" />
  <User Username="username2" Password="password2" />
</Credentials>

My Recommendation

YAML has a simple format that's relatively easy for humans to read and write, without a lot of "fluff". It's capable of handling both simple and complex objects. It's also a superset of the JSON spec, so the same parser can read JSON formatting. I'd personally choose that. The YAMLDotNet library makes parsing pretty simple:

var dict = new DeserializerBuilder().Build().Deserialize<Dictionary<string, string>>(text);

One other option to consider

Your use case sounds like exactly what ASP.NET's App Secrets (aka User Secrets) were designed to handle. Consider using their library, tooling, and conventions instead of coming up with your own.