Generating pairs

Pulizia dei dati in Python

Adel Nehme

VP of AI Curriculum, DataCamp

Motivation

NBA games tables

When joins won't work

record linkage

Record linkage

The recordlinkage package

Our DataFrames

census_A

             given_name  surname date_of_birth         suburb state  address_1
rec_id                                                                
rec-1070-org   michaela  neumann      19151111  winston hills   cal  stanley street 
rec-1016-org   courtney  painter      19161214      richlands   txs  pinkerton circuit 
...

census_B

               given_name  surname date_of_birth             suburb state  address_1
rec_id                                                                      
rec-561-dup-0       elton      NaN      19651013         windermere   ny   light setreet 
rec-2642-dup-0   mitchell    maxon      19390212         north ryde   cal  edkins street 
...

Generating pairs

Blocking

Generating pairs

# Import recordlinkage
import recordlinkage


# Create indexing object
indexer = recordlinkage.Index()


# Generate pairs blocked on state
indexer.block('state')
pairs = indexer.index(census_A, census_B)

Generating pairs

print(pairs)

MultiIndex(levels=[['rec-1007-org', 'rec-1016-org', 'rec-1054-org', 'rec-1066-org', 
'rec-1070-org', 'rec-1075-org', 'rec-1080-org', 'rec-110-org', 'rec-1146-org', 
'rec-1157-org', 'rec-1165-org', 'rec-1185-org', 'rec-1234-org', 'rec-1271-org', 
'rec-1280-org',...........  
66, 14, 13, 18, 34, 39, 0, 16, 80, 50, 20, 69, 28, 25, 49, 77, 51, 85, 52, 63, 74, 61, 
83, 91, 22, 26, 55, 84, 11, 81, 97, 56, 27, 48, 2, 64, 5, 17, 29, 60, 72, 47, 92, 12,
95, 15, 19, 57, 37, 70, 94]], names=['rec_id_1', 'rec_id_2'])

Comparing the DataFrames

# Generate the pairs
pairs = indexer.index(census_A, census_B)

# Create a Compare object
compare_cl = recordlinkage.Compare()


# Find exact matches for pairs of date_of_birth and state
compare_cl.exact('date_of_birth', 'date_of_birth', label='date_of_birth')
compare_cl.exact('state', 'state', label='state')

# Find similar matches for pairs of surname and address_1 using string similarity
compare_cl.string('surname', 'surname', threshold=0.85, label='surname')
compare_cl.string('address_1', 'address_1', threshold=0.85, label='address_1')


# Find matches
potential_matches = compare_cl.compute(pairs, census_A, census_B)

Finding matching pairs

print(potential_matches)

                             date_of_birth  state  surname  address_1
rec_id_1     rec_id_2                                                
rec-1070-org rec-561-dup-0               0      1      0.0        0.0
             rec-2642-dup-0              0      1      0.0        0.0
             rec-608-dup-0               0      1      0.0        0.0
...
rec-1631-org rec-4070-dup-0              0      1      0.0        0.0
             rec-4862-dup-0              0      1      0.0        0.0
             rec-629-dup-0               0      1      0.0        0.0
...

Finding the only pairs we want

potential_matches[potential_matches.sum(axis = 1) => 2]

                             date_of_birth  state  surname  address_1
rec_id_1     rec_id_2                                                
rec-4878-org rec-4878-dup-0              1      1      1.0        0.0
rec-417-org  rec-2867-dup-0              0      1      0.0        1.0
rec-3964-org rec-394-dup-0               0      1      1.0        0.0
rec-1373-org rec-4051-dup-0              0      1      1.0        0.0
             rec-802-dup-0               0      1      1.0        0.0
rec-3540-org rec-470-dup-0               0      1      1.0        0.0

Let's practice!

Pulizia dei dati in Python