dmypy and mypy behave differently with same settings

[kurtgn]

Consider this example:

class Config:
    url = None

    def __init__(self) -> None:
        self.url = 'xxx'

mypy says there are no errors, but dmypy with the same settings finds one:

$ mypy example.py
Success: no issues found in 1 source file

$ dmypy run -- --follow-imports=skip example.py
Daemon started
example.py:3: error: Need type annotation for 'url'
Found 1 error in 1 file (checked 1 source file)

my package versions:

$ python --version
Python 3.6.5 :: Anaconda, Inc.
$ mypy --version
mypy 0.750

[JukkaL]

Yeah, this is a known issue (but it might be undocumented). You can use --local-partial-types to get the dmypy semantics when using mypy.

At some point we'll likely make --local-partial-types enabled by default.

[kurtgn]

Thanks! Can you provide any link to docs regarding local-partial-types at least for regular mypy? I can't seem to find one on the docs webpage.

[JukkaL]

It looks like we've forgotten to document it.

[jnoortheen]

is there any config variable to set --local-partial-types in setup.cfg or similar ?

[bobwhitelock]

@jnoortheen It can be set with the local_partial_types option

Edit: Although it looks like setting this to True means it will be treated as True when running mypy as well as dmypy, as expected, but setting it to False will not override the implicit --local-partial-types when running dmypy, which seems a little surprising