Hello World

Here is a simple example implementing the above graph

#!/usr/bin/env python3

from sgn.base import SourceElement, SinkElement, Frame
from sgn.apps import Pipeline

class MySourceClass(SourceElement):
    def new(self, pad):
        return Frame(data="hello")

class MySinkClass(SinkElement):
    def pull(self, pad, frame):
        print (frame.data)

source = MySourceClass(source_pad_names = ("a",))
sink = MySinkClass(sink_pad_names = ("x",))

pipeline = Pipeline()

pipeline.insert(source, sink, link_map = {sink.snks["x"]: source.srcs["a"]})

pipeline.run()

If you run this, it will run forever and you will see

hello
hello
hello
hello
hello
hello
hello
hello
hello
hello
...

You would need to send SIG INT or SIG kill to stop the program.