[DSpinellis]

I've found creating pipelines with Python to be messy and intuitive. Other than creating a DSL to express them I can't see how DAGs can be expressed naturally with Python's syntax.

Even creating tools in Python that can be connected together in a Unix shell pipeline isn't trivial. By default if a downstream program stops processing Python's output you get an unsightly broken pipe exception, so you need to execute signal.signal(signal.SIGPIPE, signal.SIG_DFL) to avoid this.