If you can run the python package on its own (without julia) in order to verify that the issue is with the python package, then it would be best to ask the folks that develop the package about it.
In python you can indeed specify encoding when processing strings, but that is for a select few built-in operations. The encoding keyword argument is not some language feature that is available everywhere: it is just a function argument that might exists if the person writing the function decides to use is as a name for one of the function arguments - just like any other function argument.
Check this post on a couple of pointers on how to use Markdown when posting code and error messages (makes it a bit easier to read and comment about it on most platforms like discourse or github) Please read: make it easier to help you