Python 3.7 support

[mikmatko]

async is a reserved keyword in Python 3.7.
async is used a bit in kafka-python, so this currently breaks Python 3.7 compatibility. See e.g. producer/base.py

Using something like async_ would be fine though, so quickest way to resolve this would be just to rename a few things from async to async_ or something like that.

Thanks!

[dpkp]

This requires a breaking change to the SimpleProducer interface (renaming the public async=True kwarg to something else). So we will need to be careful about how we roll this out.

[tvoinarovskyi]

Just use kwargs...

[dpkp]

We wont be able to keep the async kwarg:

Python 3.7.0b2 (default, Mar 22 2018, 10:48:35)
[Clang 9.0.0 (clang-900.0.39.2)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> def foo(async=True):
  File "<stdin>", line 1
    def foo(async=True):
                ^
SyntaxError: invalid syntax
>>>

Which means we are going to have to break the current interface...

[tvoinarovskyi]

I meant something like:

>>> def send(self, **kwargs):
...     if 'async' in kwargs:
...         print(kwargs['async'])
... 
>>> send(1)
>>> send(1, async=True)
True

[dpkp]

Nice! So passing async=True would still work on older pythons. Great call.

[dpkp]

Fixed in #1454

[ATajadod94]

Issue persists on pip install as of today

[ghost]

Issue persists on pip install as of today

You need to pip uninstall kafka and then pip install kafka-python
The package named kafka is still with an older version without the fix, but the package kafka-python is up to date...