[Python-ideas] TypeHinting: From variable name to type

[Anders Hovmöller]

> On 19 Oct 2018, at 09:18, Thomas Güttler <guettliml at thomas-guettler.de> wrote:
> 
> Imaging you are developing in the django context.
> 
> Everytime you use a variable named "request" or "response" your human brains
> knows that this is a subclass of  django.http.HttpRequest and django.http.HttpResponse.
> 
> How to give the IDE this knowledge?
> 
> One solution is the do typehinting everywhere the veriable gets used.
> 
> But why does the human brain not need this?
> 
> Because it is intelligent?
> 
> I would not call this intelligence. There is a simple
> dictionary in the brain of the developer, which maps:
> 
> variable-name --> Type
> 
> And this mapping dict exists once per library.
> 
> If you are developing in the requests http lib, then
> there is a different mapping. Then "response" means
> type requests.Response.
> 
> 
> Now my idea: Per module and/or per file type hinting from variable name.
> 
> Maybe a magic docstring in the __init__.py file:
> 
> """
> variable-name-mapping:
> {
>   request: django.http.HttpRequest,
> ...
> }
> """
> 
> This makes the type mapping available for all files in this directory (or sub-directories).
> 
> What do you think?


I tried to implement this in mypy quite recently actually, but gave up for various reasons.

I am very much +1 on this. This would be a huge boon to preexisting code bases.

/ Anders