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#pydruid pydruid exposes a simple API to create, execute, and analyze Druid queries. pydruid can parse query results into Pandas DataFrame objects for subsequent data analysis -- this offers a tight integration between Druid, the SciPy stack (for scientific computing) and scikit-learn (for machine learning). Additionally, pydruid can export query results into TSV or JSON for further processing with your favorite tool, e.g., R, Julia, Matlab, Excel.

To install:

pip install pydruid

Documentation: https://pythonhosted.org/pydruid/.

#examples The following exampes show how to execute and analyze the results of three types of queries: timeseries, topN, and groupby. We will use these queries to ask simple questions about twitter's public data set.

timeseries

What was the average tweet length, per day, surrounding the 2014 Sochi olympics?

from pydruid.client import *
from pylab import plt

query = PyDruid(druid_url_goes_here, 'druid/v2')

ts = query.timeseries(
    datasource='twitterstream',
    granularity='day',
    intervals='2014-02-02/p4w',
    aggregations={'length': doublesum('tweet_length'), 'count': doublesum('count')},
    post_aggregations={'avg_tweet_length': (Field('length') / Field('count'))},
    filter=Dimension('first_hashtag') == 'sochi2014'
)
df = query.export_pandas()
df['timestamp'] = df['timestamp'].map(lambda x: x.split('T')[0])
df.plot(x='timestamp', y='avg_tweet_length', ylim=(80, 140), rot=20,
        title='Sochi 2014')
plt.ylabel('avg tweet length (chars)')
plt.show()

alt text

topN

Who were the top ten mentions (@user_name) during the 2014 Oscars?

top = query.topn(
    datasource='twitterstream',
    granularity='all',
    intervals='2014-03-03/p1d',  # utc time of 2014 oscars
    aggregations={'count': doublesum('count')},
    dimension='user_mention_name',
    filter=(Dimension('user_lang') == 'en') & (Dimension('first_hashtag') == 'oscars') &
           (Dimension('user_time_zone') == 'Pacific Time (US & Canada)') &
           ~(Dimension('user_mention_name') == 'No Mention'),
    metric='count',
    threshold=10
)

df = query.export_pandas()
print df

   count                 timestamp user_mention_name
0   1303  2014-03-03T00:00:00.000Z      TheEllenShow
1     44  2014-03-03T00:00:00.000Z        TheAcademy
2     21  2014-03-03T00:00:00.000Z               MTV
3     21  2014-03-03T00:00:00.000Z         peoplemag
4     17  2014-03-03T00:00:00.000Z               THR
5     16  2014-03-03T00:00:00.000Z      ItsQueenElsa
6     16  2014-03-03T00:00:00.000Z           eonline
7     15  2014-03-03T00:00:00.000Z       PerezHilton
8     14  2014-03-03T00:00:00.000Z     realjohngreen
9     12  2014-03-03T00:00:00.000Z       KevinSpacey

groupby

What does the social network of users replying to other users look like?

from igraph import *
from cairo import *
from pandas import concat

group = query.groupby(
    datasource='twitterstream',
    granularity='hour',
    intervals='2013-10-04/pt12h',
    dimensions=["user_name", "reply_to_name"],
    filter=(~(Dimension("reply_to_name") == "Not A Reply")) &
           (Dimension("user_location") == "California"),
    aggregations={"count": doublesum("count")}
)

df = query.export_pandas()

# map names to categorical variables with a lookup table
names = concat([df['user_name'], df['reply_to_name']]).unique()
nameLookup = dict([pair[::-1] for pair in enumerate(names)])
df['user_name_lookup'] = df['user_name'].map(nameLookup.get)
df['reply_to_name_lookup'] = df['reply_to_name'].map(nameLookup.get)

# create the graph with igraph
g = Graph(len(names), directed=False)
vertices = zip(df['user_name_lookup'], df['reply_to_name_lookup'])
g.vs["name"] = names
g.add_edges(vertices)
layout = g.layout_fruchterman_reingold()
plot(g, "tweets.png", layout=layout, vertex_size=2, bbox=(400, 400), margin=25, edge_width=1, vertex_color="blue")

alt text