This didn't fix the problem.
When I do this, pypmml does "see" this version, as when I later install pypmml, it skips the py4j requirement install and cites the py4j location from the show command. However, I still get the same error.
I don't know how to make pypmml know where to look to find the right py4j jar.
Also, even when I install py4j in this way, the databricks environment still seems to point to a different py4j install. If I run:
import py4j
print(py4j.__version__)
print(py4j.__file__)
I get a different version and path than what was specified/returned from the install commands.