`tempfile.SpooledTemporaryFile` missing `_file` attribute

[Dr-Irv]

According to the python docs, SpooledTemporaryFile._file is an attribute: "The returned object is a file-like object whose _file attribute is either an io.BytesIO or io.TextIOWrapper object (depending on whether binary or text mode was specified)"

So the _file attribute should be added to tempfile.pyi for the SpooledTemporaryFile class.

[sobolevn]

It is documented indeed (which is rare for protected names). Please, feel free to send a PR with the fix.

[heysujal]

Hi, I want to work on this issue, but I am not able to understand where should I make changes in

typeshed/stdlib/tempfile.pyi

Line 361 in 8e4595a

class SpooledTemporaryFile(IO[AnyStr], _SpooledTemporaryFileBase):

[Akuli]

The new _file attribute will be pretty similar to the existing encoding attribute, so you could make a copy of that to get started. In the stub, encoding is a method decorated with @property, which means that it is actually a read-only attribute and not really a method.

>>> import tempfile
>>> f = tempfile.SpooledTemporaryFile(mode='w+')
>>> f.encoding
'UTF-8'
>>> f._file
<_io.TextIOWrapper encoding='UTF-8'>

The difference is that _file should not be a str, but one of two things depending on the mode. You can use @overload to achieve that. Look at write() and writelines(), for example.

[heysujal]

@Akuli thanks for the help. I am now working on it.

[heysujal]

@sobolevn @AlexWaygood Sorry for the delay. I have made a PR ,please review it.