mypy suite is not run with strict mode and many typing errors still remain

[marcinbarczynski]

Describe the bug

In a basic checking mode, pyright reports an error when importing a symbol from a module that is not re-exported using import ... as ... convention. In alembic.util package __init__.py imports symbols from other modules within the package.
I assume the intention was to re-export the imported symbols.

Expected behavior

No error reported by pyright.

To Reproduce

from alembic.util import coerce_resource_to_filename

def fun():
    coerce_resource_to_filename("A")

Error

$ pyright ../demo.py 
/path/to/demo.py
  /path/to/demo.py:1:26 - error: "coerce_resource_to_filename" is not exported from module "alembic.util"
    Import from "alembic.util.pyfiles" instead (reportPrivateImportUsage)
1 error, 0 warnings, 0 informations 

Versions.

• OS: Linux
• Python: 3.11.5
• pyright: 1.1.339
• Alembic: 1.13.0

Have a nice day!

[zzzeek]

hi -

I'm not able to get pyright to report an error on the script above (nor mypy). I am trying to put pyright into fully strict mode as well:

pyrightconfig.json

{
    "typeCheckingMode": "strict"
}

no errors:

$ PYTHONPATH=~/dev/sqlalchemy/lib/ pyright  test3.py 
0 errors, 0 warnings, 0 informations 

I agree that type checkers often complain about imports not being exported but that is not happening here for either tool, and we most certainly do have a full strict mypy run for alembic in CI which passes.

[zzzeek]

wow did not intend to close this, sorry!!

[zzzeek]

cc @CaselIT , you might be more familiar with the rules for how exported symbols work w typing

[CaselIT]

Isn't it the fact that they insist on having stuff exported with from bar import foo as foo?

I'm not too sure if all things in alembic.util should be considered public though

[zzzeek]

sure, just want to understand what the rules are because we definitely had to add these exports in sqlalchemy

[marcinbarczynski]

I'm not able to get pyright to report an error on the script above

I'm surprised you can't reproduce it.

These are the step to reproduce from scratch:

$ mkvirtualenv demo
(demo) $ pip install pyright
(demo) $ pip install alembic
(demo) $ cat > demo.py <<EOF
> from alembic.util import coerce_resource_to_filename

def fun():
    coerce_resource_to_filename("A")
> EOF
(demo) $ pyright demo.py
/tmp/demo.py
  /tmp/demo.py:1:26 - error: "coerce_resource_to_filename" is not exported from module "alembic.util"
    Import from "alembic.util.pyfiles" instead (reportPrivateImportUsage)
1 error, 0 warnings, 0 informations 

In strict mode:

(demo) $ cat >pyrightconfig.json <<EOF
> {
    "typeCheckingMode": "strict"
}
> EOF
(demo) $ pyright -p pyrightconfig.json demo.py
/tmp/demo.py
  /tmp/demo.py:1:26 - error: "coerce_resource_to_filename" is not exported from module "alembic.util"
    Import from "alembic.util.pyfiles" instead (reportPrivateImportUsage)
1 error, 0 warnings, 0 informations 

The same result on two separate machines.

[dybi]

I concur - reproduced on
22.04.1-Ubuntu with Python 3.10.12
alembic 1.13.0
pyright 1.1.340

[zzzeek]

do the rules for typing change when I am running pyright from within the source tree of alembic itself? I've looked all around to see if I have any pyright configs (or mypy configs) that would cancel it out.

Here's a run from an editable install, I added newlines between my commands and you can see the output

[classic@framework tmp]$ git clone https://github.com/sqlalchemy/alembic
Cloning into 'alembic'...
remote: Enumerating objects: 14513, done.
remote: Counting objects: 100% (1714/1714), done.
remote: Compressing objects: 100% (154/154), done.
remote: Total 14513 (delta 1578), reused 1578 (delta 1552), pack-reused 12799
Receiving objects: 100% (14513/14513), 3.72 MiB | 31.19 MiB/s, done.
Resolving deltas: 100% (10451/10451), done.

[classic@framework tmp]$ cd alembic/

[classic@framework alembic:main]$ cat > demo.py <<EOF
> from alembic.util import coerce_resource_to_filename
> def fun():
    coerce_resource_to_filename("A")
> EOF

[classic@framework alembic:main]$ virtualenv .venv
created virtual environment CPython3.12.0.final.0-64 in 83ms
  creator CPython3Posix(dest=/home/classic/tmp/alembic/.venv, clear=False, no_vcs_ignore=False, global=False)
  seeder FromAppData(download=False, pip=bundle, via=copy, app_data_dir=/home/classic/.local/share/virtualenv)
    added seed packages: pip==23.3.1
  activators BashActivator,CShellActivator,FishActivator,NushellActivator,PowerShellActivator,PythonActivator

[classic@framework alembic:main]$ .venv/bin/pip install -e .
Obtaining file:///home/classic/tmp/alembic
  Installing build dependencies ... done
  Checking if build backend supports build_editable ... done
  Getting requirements to build editable ... done
  Installing backend dependencies ... done
  Preparing editable metadata (pyproject.toml) ... done
Collecting SQLAlchemy>=1.3.0 (from alembic==1.13.1.dev0)
  Using cached SQLAlchemy-2.0.23-cp312-cp312-manylinux_2_17_x86_64.manylinux2014_x86_64.whl.metadata (9.6 kB)
Collecting Mako (from alembic==1.13.1.dev0)
  Using cached Mako-1.3.0-py3-none-any.whl.metadata (2.9 kB)
Collecting typing-extensions>=4 (from alembic==1.13.1.dev0)
  Using cached typing_extensions-4.9.0-py3-none-any.whl.metadata (3.0 kB)
Collecting greenlet!=0.4.17 (from SQLAlchemy>=1.3.0->alembic==1.13.1.dev0)
  Using cached greenlet-3.0.2-cp312-cp312-manylinux_2_24_x86_64.manylinux_2_28_x86_64.whl.metadata (3.7 kB)
Collecting MarkupSafe>=0.9.2 (from Mako->alembic==1.13.1.dev0)
  Using cached MarkupSafe-2.1.3-cp312-cp312-manylinux_2_17_x86_64.manylinux2014_x86_64.whl.metadata (2.9 kB)
Using cached SQLAlchemy-2.0.23-cp312-cp312-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (3.2 MB)
Using cached typing_extensions-4.9.0-py3-none-any.whl (32 kB)
Using cached Mako-1.3.0-py3-none-any.whl (78 kB)
Using cached greenlet-3.0.2-cp312-cp312-manylinux_2_24_x86_64.manylinux_2_28_x86_64.whl (621 kB)
Using cached MarkupSafe-2.1.3-cp312-cp312-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (28 kB)
Building wheels for collected packages: alembic
  Building editable for alembic (pyproject.toml) ... done
  Created wheel for alembic: filename=alembic-1.13.1.dev0-0.editable-py3-none-any.whl size=6643 sha256=1937db6bed089b82324d9cb693a384a9a1ac9401c363114fb2a3b9e3b56367bd
  Stored in directory: /tmp/pip-ephem-wheel-cache-pa8ba87q/wheels/06/ef/a0/2d7a25e036fc488876ab25c0fc0386326a019996c54cccdb2f
Successfully built alembic
Installing collected packages: typing-extensions, MarkupSafe, greenlet, SQLAlchemy, Mako, alembic
Successfully installed Mako-1.3.0 MarkupSafe-2.1.3 SQLAlchemy-2.0.23 alembic-1.13.1.dev0 greenlet-3.0.2 typing-extensions-4.9.0

[classic@framework alembic:main]$ .venv/bin/pip install pyright
Collecting pyright
  Downloading pyright-1.1.340-py3-none-any.whl.metadata (6.2 kB)
Collecting nodeenv>=1.6.0 (from pyright)
  Downloading nodeenv-1.8.0-py2.py3-none-any.whl.metadata (21 kB)
Collecting setuptools (from nodeenv>=1.6.0->pyright)
  Using cached setuptools-69.0.2-py3-none-any.whl.metadata (6.3 kB)
Downloading pyright-1.1.340-py3-none-any.whl (18 kB)
Downloading nodeenv-1.8.0-py2.py3-none-any.whl (22 kB)
Using cached setuptools-69.0.2-py3-none-any.whl (819 kB)
Installing collected packages: setuptools, nodeenv, pyright
Successfully installed nodeenv-1.8.0 pyright-1.1.340 setuptools-69.0.2

[classic@framework alembic:main]$ .venv/bin/pyright demo.py 

added 1 package, and audited 2 packages in 1s

found 0 vulnerabilities
0 errors, 0 warnings, 0 informations 
[classic@framework alembic:main]$ 

it does reproduce with a non-editable install and plain venv though

[zzzeek]

it looks like for mypy we have not yet turned on strict mode in our pyproject.toml, so that's really what has to be fixed here