Support namespace packages from command line

[gvanrossum]

Currently the --namespace-packages option only applies to imported modules. Files, modules and packages specified on the command line (as files or with -p or -m) cannot be in namespace packages. We should fix this.

Follow-up to #5591.

[gvanrossum]

Update: -m honors --namespace-packages just fine. It's just -p and specifying files on the command line that don't. With -p I get Can't find package 'foo.bar' and when specifying the full path mypy assumes the top-level namespace (foo) is not a package at all.

[asottile]

I have a similar problem. Here's a minimal reproduction:

$ mypy --version
mypy 0.641
$ mkdir {a,b} && touch {a,b}/a.py
$ mypy a/a.py b/a.py --namespace-packages
b/a.py: error: Duplicate module named 'a'

I'm working around this by adding __init__.py files. Note that I'm invoking in this way as I'm using mypy with pre-commit via mirrors-mypy

[tsibley]

I'm running into this issue. While -m works with --namespace-packages, that means I have to specify every module in my package individually on the command-line; this is not nearly as nice as just running mypy foo.

[gvanrossum]

It's on our list of issue, but that list is rather long. Perhaps one of you is interested in submitting a PR to help this along more quickly?

[tsibley]

It seems as if @rafales started on addressing this: master...rafales:namespace-packages

I might be able to find the time to make a PR, but would appreciate some guidance on where to start in order to save myself a lot of bootstrapping time understanding how mypy is put together.

[russellwinstead]

It looks like it comes down to the options not being passed to the FindModuleCache object here:

mypy/mypy/main.py

Lines 783 to 784 in b027308

	# TODO: use the same cache that the BuildManager will
	cache = FindModuleCache(search_paths, fscache)

[rafales]

It's more complicated, right now mypy relies on the existence of __init__.py files to figure out package name. If you end up with subpackage named the same as a global package, you'll end up with confusing errors (eg. "mycompany.graphql" and "graphql"). I did start looking into the problem and fixed it enough to work for my usecase on the branch mentioned above. But it still needs some work before turning it into PR.

…

On Fri, Feb 1, 2019 at 9:47 PM russellwinstead ***@***.***> wrote: It looks like it comes down to the options not being passed to the FindModuleCache object here: https://github.com/python/mypy/blob/b027308116d19dc79bf80334ff06aab7c0001e11/mypy/main.py#L783-L784 — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or mute the thread.

[gvanrossum]

Thanks!