count
The count
reducer simply counts the number of points that have passed
through this point in the pipeline.
counting points
from flume import *
(
emit(limit=10, start='2015-01-01')
| reduce(count=count())
| write('stdio')
).execute()
The above would produce the output:
{"count": 10, "time": "2015-01-01T00:00:00.000Z"}