from disco.job import Job
from disco.worker.classic.func import chain_reader

class FirstJob(Job):
    input = ['raw://0', 'raw://0']

    @staticmethod
    def map(line, params):
        yield int(line) + 1, ""

class ChainJob(Job):
    map_reader = staticmethod(chain_reader)

    @staticmethod
    def map(key_value, params):
        yield int(key_value[0]) + 1, value

if __name__ == "__main__":
    last = FirstJob().run()
    for i in xrange(9):
        last = ChainJob().run(input=last.wait())
    print(last.name)

@@ -359,21 +359,28 @@
 %5D) + 1, 
+key_
 value
+%5B1%5D
 %0A%0Aif __n

fix a syntax fix in example.