Load up packages.



In [8]:

    
%matplotlib inline
import numpy as np
import pandas as pd
import urllib2

Read in data.



In [11]:

    
data = pd.read_csv(urllib2.urlopen('http://forever.codeforamerica.org/fellowship-2015-tech-interview/Violations-2012.csv'))
data.head()









    Out[11]:






  
    
      
      violation_id
      inspection_id
      violation_category
      violation_date
      violation_date_closed
      violation_type
    
  
  
    
      0
       204851
       261019
          Garbage and Refuse
       2012-01-03 00:00:00
       2012-02-02 00:00:00
                        Refuse Accumulation
    
    
      1
       204852
       261019
       Unsanitary Conditions
       2012-01-03 00:00:00
       2012-02-02 00:00:00
       Unsanitary conditions, not specified
    
    
      2
       204853
       261023
          Garbage and Refuse
       2012-01-03 00:00:00
       2012-01-17 00:00:00
                        Refuse Accumulation
    
    
      3
       204854
       261023
          Garbage and Refuse
       2012-01-03 00:00:00
       2012-01-17 00:00:00
                        Refuse Accumulation
    
    
      4
       204858
       261029
          Garbage and Refuse
       2012-01-03 00:00:00
       2012-03-12 00:00:00
                        Refuse Accumulation



In [7]:

    
# Group data on `violation_category'
data_gb_violation_category = data.groupby('violation_category')

# Use aggregation function on GroupBy object to compute summary statistics
violations = data_gb_violation_category.agg({'violation_date':
                                {'num':len,
                                 'min_date':np.min,
                                 'max_date':np.max}})
                                 
# Drop extraneous column header
violations.columns = violations.columns.droplevel(0)                                 

# Write out results to file
violations.to_csv('violations_summary.csv',encoding='utf8')

# Print out summary statistics
violations









    Out[7]:






  
    
      
      num
      max_date
      min_date
    
    
      violation_category
      
      
      
    
  
  
    
      Air Pollutants and Odors
         2
       2012-12-19 00:00:00
       2012-12-05 00:00:00
    
    
      Animals and Pests
       180
       2012-12-28 00:00:00
       2012-01-03 00:00:00
    
    
      Biohazards
         7
       2012-12-18 00:00:00
       2012-04-13 00:00:00
    
    
      Building Conditions
        62
       2012-12-26 00:00:00
       2012-01-12 00:00:00
    
    
      Chemical Hazards
        17
       2012-12-06 00:00:00
       2012-02-08 00:00:00
    
    
      Garbage and Refuse
       126
       2012-12-21 00:00:00
       2012-01-03 00:00:00
    
    
      Retail Food
         1
       2012-12-20 00:00:00
       2012-12-20 00:00:00
    
    
      Unsanitary Conditions
        83
       2012-12-19 00:00:00
       2012-01-03 00:00:00
    
    
      Vegetation
        67
       2012-12-05 00:00:00
       2012-02-01 00:00:00



In [ ]:

	violation_id	inspection_id	violation_category	violation_date	violation_date_closed	violation_type
0	204851	261019	Garbage and Refuse	2012-01-03 00:00:00	2012-02-02 00:00:00	Refuse Accumulation
1	204852	261019	Unsanitary Conditions	2012-01-03 00:00:00	2012-02-02 00:00:00	Unsanitary conditions, not specified
2	204853	261023	Garbage and Refuse	2012-01-03 00:00:00	2012-01-17 00:00:00	Refuse Accumulation
3	204854	261023	Garbage and Refuse	2012-01-03 00:00:00	2012-01-17 00:00:00	Refuse Accumulation
4	204858	261029	Garbage and Refuse	2012-01-03 00:00:00	2012-03-12 00:00:00	Refuse Accumulation

	num	max_date	min_date
violation_category
Air Pollutants and Odors	2	2012-12-19 00:00:00	2012-12-05 00:00:00
Animals and Pests	180	2012-12-28 00:00:00	2012-01-03 00:00:00
Biohazards	7	2012-12-18 00:00:00	2012-04-13 00:00:00
Building Conditions	62	2012-12-26 00:00:00	2012-01-12 00:00:00
Chemical Hazards	17	2012-12-06 00:00:00	2012-02-08 00:00:00
Garbage and Refuse	126	2012-12-21 00:00:00	2012-01-03 00:00:00
Retail Food	1	2012-12-20 00:00:00	2012-12-20 00:00:00
Unsanitary Conditions	83	2012-12-19 00:00:00	2012-01-03 00:00:00
Vegetation	67	2012-12-05 00:00:00	2012-02-01 00:00:00