buf1 != buf2 doesn't work in python2

[Yggdroot]

• nvim --version: NVIM v0.4.0-758-g9e0982a1a
• Vim (version: ) behaves differently? yes
• Operating system/version: Linux
• Terminal name/version:
• $TERM:

Steps to reproduce using nvim -u NORC

nvim -u NORC

Suppose there is a file bug.vim:

py << EOF
import vim

aaa = vim.current.buffer
print(aaa == vim.current.buffer, aaa != vim.current.buffer)

EOF

Source the file: so %

This bug only happen when using python2, It works well for python3.

Actual behaviour

Result is (True, True) .

Expected behaviour

Result is (True, False) .

[bfredl]

The reason is python2 doesn't have implicit __ne__ unlike python3. https://stackoverflow.com/questions/4352244/python-should-i-implement-ne-operator-based-on-eq

[noelevans]

I have a fix for this. It passes for both python 2.7 and 3.7.

While adding the unit test for the change, I also fixed a warning on test_buffer.py:96. Previously the module printed the warning below when run with python 3.7:
/home/noel/repo/pynvim/test/test_buffer.py:96: DeprecationWarning: invalid escape sequence \s
assert vim.options['define'] == '^\s*#\s*define'

I'm sending the pull request now