Difference between revisions of "Round"
From NoSQLZoo
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− | Rounding is easy inside a <code>MapReduce</code> as | + | Rounding is easy inside a <code>MapReduce</code> as it is possible to use the <code>Math</code> object provided by JavaScript. |
At the time of writing the <code>aggregation()</code> method has no rounding functions, though it is still doable. | At the time of writing the <code>aggregation()</code> method has no rounding functions, though it is still doable. | ||
<div class=q data-lang="py3">MapReduce | <div class=q data-lang="py3">MapReduce |
Revision as of 12:50, 26 July 2015
#ENCODING import io import sys sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-16') #MONGO from pymongo import MongoClient client = MongoClient() client.progzoo.authenticate('scott','tiger') db = client['progzoo'] #PRETTY import pprint pp = pprint.PrettyPrinter(indent=4) #CODE from bson.code import Code
Rounding is easy inside a MapReduce
as it is possible to use the Math
object provided by JavaScript.
At the time of writing the aggregation()
method has no rounding functions, though it is still doable.
MapReduce
from bson.code import Code temp = db.world.map_reduce( query={"population":{"$ne":None}}, limit=1, map=Code("function(){emit(this.name, this.population)}"), reduce=Code("function(key, values){return Math.round(values/1000000)}"), out={"inline":1}, ) pp.pprint( temp["results"] )