* move cgi to 2and3 and add types
This is pretty stable between Python 2 and 3, and not very well documented.
* fix CI failures
* adjust comment
(want to force Travis to re-run)
* give up on overriding values
- Add sys.version_info checks (mypy now supports them)
- Went over Python 3 docs and corrected a few things
- Reexport things that are imported from opcode
CONTRIBUTING.md says to prefer ... Not the most impactful change but fixing
these will allow us to lint for it in the future and get a consistent style.
"> (3,)" works but looks like the code is checking for Python 4.
"<= (3, 5)" was intended to check for versions up to and including 3.5, and probably works that
way in current type checkers. However, sys.version_info is actually a 5-tuple that is greater
than (3, 5), so a hypothetical type checker that uses the full version info would interpret
this check incorrectly.
This ensures that all version_info comparisons use <, >=, ==, or !=.
Both mypy and pytype only use the major and minor version in type checking. Using
checks like "sys.version_info >= (3, 4, 4)" won't actually work properly for
people type checking their code using version 3.4, because (3, 4) >= (3, 4, 4) will
always be false (at least in mypy's approach; not sure if pytype is different).
* Improve types for xml.etree.ElementTree
Update signatures to reflect the following peculiarities of the
ElementTree library:
- The elementtree library accepts unicode or bytes for most xml values
in python2, and coerces everywhere -- but in python3, only str makes
sense.
- In python 2, the library produces str or unicode instances
unpredictably, depending on whether the xml is decodeable as ascii or
not. In python 3, it always produces str instances.
- The parser functions accept unicode or bytes in 2 and 3 -- again, will
coerce individual instances so heterogeneous lists are ok.
- In python 3, the tostring functions produce bytes or str, depending on
the value of the 'encoding' parameter.
* improve docs
* Improve ElementFactory type by specifying dict of 2nd arg
Change `str` to `Union[str, unicode]` where it seems safe.
I didn't change it in non-covariant contexts since that can
break user code.
I manually verified a subset of the changes by calling the
relevant function with unicode literals (ascii-only).
I'm using `Union[str, unicode]` instead of just `unicode`
so that the stub still works with tools that don't promote
`str` objects to `unicode`.
According to the documentation in the typing module, TypeVars cannot
have only a single constraint. Attempting to do so will actually result
in an exception at runtime. (However, this error is currently ignored
by mypy -- see https://github.com/python/mypy/pull/2626 for a related
pending pull request).
This commit changes all instances of TypeVars using a single constraint
(e.g. `T = TypeVar('T', Foo)`) to use bounds instead (e.g.
`T = TypeVar('T', bound=Foo)`.
This seems to be the correct fix for plistlib after reading the module
docs, but it's less obvious this is correct for unittest. The unittest
module originally had `_FT = TypeVar('_FT', Callable[[Any], Any])` -- an
alternative fix would have been to do `_FT = Callable[[Any], Any]`.
Although I'm not entirely sure what it means to have a bound be a
Callable, I decided to make the assumption that the original authors
probably meant to use TypeVars instead of type aliases for a reason
(possibly to handle classes implementing `__call__`?)
