can a target have two SourceFields? i.e. a python and a yaml field?

Not really, unfortunately. The Target API won't be happy when you say

tgt.get(SourcesField)

one of my targets needs both YAML and Python

Also fyi there is

SecondaryOwnerMixin

so that you get file-like benefits, like that a file argument still works on the target This is how

pex_binary

works. It does not "own" the file

entry_point=main.py

, yet you can still do

./pants run project/main.py

That one is safe to use on as many targets as you'd like

yeah you're right

for

pex_binary

, the gist is: 1. ensure the

python_source

target is in the

dependencies

(e.g. via dep inference rule) 2. in your rule to build stuff, use

SourceFiles

or

PythonSourceFiles

to get the Python file + all its deps present 3. Also use

SecondaryOwnerMixin

for nice semantics

why can I do tgt.get(SourcesField) and not tgt.get(PythonSourceField)

what do you mean?

I think I resolved it. But tg.tget(PythonSourceField) errors with

you must define sources on the target

or

StrippedSourceFiles