pyflakes found the following issues in sendall():

Lib/test/mock_socket.py:95:21 undefined name 'data'
Lib/test/mock_socket.py:96:28 undefined name 'data'
Lib/test/mock_socket.py:97:20 undefined name 'data'

Code:

    def sendall(self, buffer, flags=None):
        self.last = data
        self.output.append(data)
        return len(data)

    def send(self, data, flags=None):
        self.last = data
        self.output.append(data)
        return len(data)

I guess that sendall() buffer parameter should be renamed to data.

Another one:

Lib/test/test_frame.py:53:17 undefined name 'inner'

I guess that self.inner() should be used instead of inner(). In practice, it's dead code, but fixing it would make pyflakes happier :-)

Another one:

Lib/test/test_json/test_recursion.py:55:24 undefined name 'pyjson'

Code:

    def test_defaultrecursion(self):
        class RecursiveJSONEncoder(self.json.JSONEncoder):
            recurse = False
            def default(self, o):
                if o is JSONTestObject:
                    if self.recurse:
                        return [JSONTestObject]
                    else:
                        return 'JSONTestObject'
                return pyjson.JSONEncoder.default(o)

Here I'm not sure. *Maybe* pyjson.JSONEncoder should be replaced with self.json.JSONEncoder?

Another one:

Lib/unittest/test/test_program.py:191:40 undefined name 'hasInstallHandler'

Code:

    def testBufferCatchFailfast(self):
        program = self.program
        for arg, attr in (('buffer', 'buffer'), ('failfast', 'failfast'),
                      ('catch', 'catchbreak')):
            if attr == 'catch' and not hasInstallHandler:
                continue
            ...

attr is never equal to 'catch' and so it's just dead code which can be removed.

Hello,
I sent a PR that corrects variable and function names.
I'm not sure how to fix it for Lib/test/test_json/test_recursion.py:55:24 so I didn't make any changes.

New changeset 719e14d2837520c18398a3e22a36f20c1fe76edf by Furkan Önder in branch 'master':
bpo-40462: fix variable and function names (GH-19832)
https://github.com/python/cpython/commit/719e14d2837520c18398a3e22a36f20c1fe76edf

@vstinner
IMHO we should create backport patch for 3.8 and 3.7
3.8 and 3.7 has same codes for this.

https://github.com/python/cpython/blob/3.8/Lib/test/mock_socket.py#L95

> IMHO we should create backport patch for 3.8 and 3.7

It's deadcode, I don't think that it's worth it. But it's up to you. If you consider that it's worth it, go ahead and backport the fix.

New changeset 4b972faf605912092013a1fdbf486c498d002926 by Victor Stinner in branch 'master':
bpo-40462: Fix typo in test_json (GH-20094)
https://github.com/python/cpython/commit/4b972faf605912092013a1fdbf486c498d002926

Thanks for the fix Furkan Önder!

You are welcome :=)