Question: Should I not be using Mode (FileMode)?

[haxsaw]

It's been suggested to me that Mode (FileMode) is not for 'real world' use for formatting code fragments in memory prior to writing to a file. Besides FileMode being legacy and probably should be replaced with just Mode, is there any reason not to use it in a system where I want to format in memory?

[felix-hilden]

If you're referring to the classes inside Black's source, the answer is: you should probably not be using them for formatting of any sort because their implementation (or existence) may change at any time. A public Python api is being planned in #779. It would most likely introduce a single function for formatting code as strings.

[haxsaw]

That's a shame, but I get it. I'm generating code dynamically and have been using black to format each class as I go (I can see from 779 that I have company). I'll consider my options. Thanks for the swift reply.

[felix-hilden]

You're most welcome! Yeah let's hope that the API is introduced soon 😃 until then, I'd not expect the implementation to change drastically, but you might want to be careful as always, that's all.

[JelleZijlstra]

However, the public API is quite likely to look like black.format_str(mode=Mode()). FileMode is a deprecated alias for Mode I believe (might be the other way around). If I were you, I'd use format_str() and be careful the next few times Black makes a release.