add universaldetector

[ju-sh]

Started adding files for chardet. Hopefully others will hop in to finish.

[srittau]

Thank you! A few remarks below.

__init__.pyi should look like this (minus the explanatory comments):

# The following line will re-export UniversalDetector like the implementation does.
# The "as ..." part is required for re-export in stubs.
from .universaldetector import UniversalDetector as UniversalDetector

# The next line will mark this stub as incomplete.
def __getattr__(name: str) -> Any: ...  # incomplete

[srittau]

While TypedDict is only available in typing starting in Python 3.8, you can just import it from typing_extensions for earlier Python versions:

if sys.version_info >= (3, 8):
    from typing import TypedDict
else:
    from typing_extensions import TypedDict

Type checkers support this. This way you would avoid the version checks below and make the typed dicts work with all Python versions.

[JelleZijlstra]

Even easier, you can also just do from typing_extensions import TypedDict so you don't need the version check.

[ju-sh]

Thanks for that both of you! Sotyping_extensions has the required info anyway?

[ju-sh]

@JelleZijlstra Stubs of some other modules seems to be doing the version check as @srittau mentioned. As in

if sys.version_info >= (3, 8):
    from typing import Final
else:
    from typing_extensions import Final

from stdlib/3/dbm/dumb.pyi

Does this method have any advantage?

[srittau]

No advantage, except that whenever 3.7 support ends, a simple grep for "version_info" will flag this. But we should just grep for typing_extensions when that happens.

[ju-sh]

You mean when typing_extensions stop supporting 3.7?

[JelleZijlstra]

No, when typeshed stops supporting 3.7 in a few years, we can just do from typing import Final in typeshed.

[srittau]

Looks good, just two more suggestions.

[srittau]

Since this is a typestub-only type, it should start with an underscore.

[srittau]

This too.

[ju-sh]

And I had a doubt. If I have a set of files all of which use a specific TypedDict class for typing. Should I include the TypedDict class in all these files or is there a way I can define it in one place and import it into those files?

[JelleZijlstra]

You can just import it from another file.

[ju-sh]

Just like python modules? Cool.

[ju-sh]

@JelleZijlstra Are there any conventions to be followed for the.pyifile where the TypedDict class is defined? The definition which can then be imported to other files?

[JelleZijlstra]

The name should probably be prefixed with _ to indicate that it doesn't exist at runtime.

[ju-sh]

Got another doubt. Can you help me out?

I came across a line like this:

if sys.version_info < (3, 0):
    base_str = (str, unicode)
else:
    base_str = (bytes, str)

What should be the type of base_str? I figure it starts with something like Tuple[Type] but couldn't be sure. What do you think?

[ju-sh]

@JelleZijlstra I think I found another way to keep the common class definition in one place. Just defined it inside the __init__.pyi file. Can then load with from . import <type>.