from .x import y causes "Name already defined" for x

[douglas-treadwell]

I believe this is different than #2135.

In this case, if I have a star import like...

#a.py
import * from b
import * from c

#b.py
from .x import y

#c.py
from .x import z

I get a "Name 'x' is already defined" error.

But the name x is not exported by b or c.

[ilevkivskyi]

Python runtime semantics is such that from .x import y leads to adding a name x to the parent module namespace, and mypy follows this semantics. But then there is a whole bunch of issues when "redefining" modules, see #1297. This particular one however, seems to be easier to solve, since we import twice exactly the same module, and normally mypy allows this.

[thomascellerier]

I got hit by this exact same bug, had to resort to import x instead of from x import y to make mypy happy (using mypy 0.590).

[NeilGirdhar]

I'm getting the reverse of this: https://github.com/NeilGirdhar/tikzify/blob/master/tikzify/__init__.py gives

tikzify/__init__.py:5: error: Name "foundation" is not defined
tikzify/__init__.py:6: error: Name "function_graph" is not defined
tikzify/__init__.py:7: error: Name "node_graph" is not defined