AGGREGATE world: Difference between revisions
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<div class="hint" title="How to calculate per capita GDP"> | <div class="hint" title="How to calculate per capita GDP"> | ||
per capita GDP is the GDP divided by the population GDP/population | per capita GDP is the GDP divided by the population GDP/population | ||
</div> | </div> | ||
<pre class=def> | <pre class=def> | ||
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)) | )) | ||
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<div class=ans> | <div class=ans>pp.pprint(list(db.world.aggregate([{"$match":{"population":{"$gte":200000000}}},{"$project":{"_id":0,"name":1,"per capita GDP": {"$divide": ["$gdp","$population"]}}}]))) | ||
pp.pprint(list( | |||
)) | |||
</div> | </div> | ||
</div> | </div> | ||
Revision as of 13:22, 16 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)
Country Profile
For these questions you should use aggregate([]) on the collection world
Give the name and the per capita GDP for those countries with a population of at least 200 million.
per capita GDP is the GDP divided by the population GDP/population
pp.pprint(list(
db.world.aggregate([
{"$match":{
"population":{"$gte":250000000}
}},
{"$project":{
"_id":0,
"name":1,
"per capita GDP": {"$divide": ["$gdp",1000000]}
}}
])
))
pp.pprint(list(db.world.aggregate([{"$match":{"population":{"$gte":200000000}}},{"$project":{"_id":0,"name":1,"per capita GDP": {"$divide": ["$gdp","$population"]}}}])))