Python：从 FuzzyWuzzy ExtractOne() 返回 Pandas DataFrame

Question

我有两个 Pandas DataFrames（人名），一个很小（200+ 行），另一个非常大（100k+ 行）。它们都有相似的标题，但大的也有一个唯一的 ID，如下所示：

Small: LST_NM, FRST_NM, CITY
Big: LST_NM, FRST_NM, CITY, UNIQUE_ID

小号：df2 = pd.DataFrame([['Doe','John','New York'], ['Obama', 'Barack', 'New York']], columns = ['FRST_NM', 'LST_NM', 'CITY_NM'])

大：df = pd.DataFrame([['Doe','John','New York', 'N1'], ['Obama', 'Barack Hussein', 'New York', 'N2'], ['Obama', 'Michelle', 'Chicago', 'N3'], ['Trump', 'Donald', 'New York', 'N4']], columns = ['FRST_NM', 'LST_NM', 'CITY_NM', 'UNIQUE_ID'])

我使用下面的代码：

import itertools
from fuzzywuzzy import fuzz
from fuzzywuzzy import process
import time
import pandas as pd
import multiprocessing as mp
from unidecode import unidecode
import re

#read the CSV files;
df = pd.read_csv("BIG.csv", encoding="utf-8")
df2 = pd.read_csv("SMALL.csv", encoding="utf-8")

#create function to clean the columns
def clean_column(column):
    column = unidecode(column)
    column = re.sub('\n', ' ', column)
    column = re.sub('-', ' ', column)
    column = re.sub('/', ' ', column)
    column = re.sub("'", '', column)
    column = re.sub(",", '', column)
    column = re.sub(":", ' ', column)
    column = re.sub('  +', ' ', column)
    column = column.strip().strip('"').strip("'").lower().strip()
    if not column :
        column = None
    return column

#Normalize, create FULL_NM by combining FRST_NM / LST_NM and then create MIN_CITY as the first three chars from CITY_NM:
df['FULL_NM'] = (df['LST_NM'] + ' ' + df['FRST_NM']).apply(lambda x: fuzz._process_and_sort(clean_column(x), True, True))
df['MIN_CITY'] = (df['CITY_NM']).astype(str).apply(lambda x: clean_column(x[:3]))

df2['FULL_NM'] = (df2['LST_NM'] + ' ' + df2['FRST_NM']).apply(lambda x: fuzz._process_and_sort(clean_column(x), True, True))
df2['MIN_CITY'] = (df2['CITY_NM']).astype(str).apply(lambda x: clean_column(x[:3]))

#create match1 function; it uses the FULL_NM as lookup field
def match1(x, choices, scorer, cutoff):
        match = process.extractOne(x['FULL_NM'], choices=choices.loc[choices['MIN_CITY'] == x['MIN_CITY'],'FULL_NM'], 
                                   scorer=scorer, 
                                   score_cutoff=cutoff)
        if match:
            return match[0]

#and finally... create the MATCH_NM column by applying match1 function as following:
df2['MATCH_NAME'] = df2.apply(match1, args=(df, fuzz.token_set_ratio, 80), axis=1)

我想从大的到小的查找信息，带上 UNIQUE_ID。为了加快这个过程，我创建了更小的块（使用城市的前三个字母）。这个新列（在两个 DataFrame 中创建）被命名为 MIN_CITY。

上面的代码运行良好，但它只带来了匹配的名称 (MATCH_NAME)。我不想反转（从小到大然后过滤）。如何从 process.ExtractOne() 中获取 UNIQUE_ID？我需要提一下，我对 Python / Pandas / FuzzyWuzzy 非常陌生。

Answer 1

请查看fuzzymatcher:

from fuzzymatcher import link_table, fuzzy_left_join

left_on = ['FULL_NM']
right_on = ['FULL_NM']

fuzzy_left_join(df2, df, left_on, right_on)

给出一个表格：

best_match_score    __id_left   __id_right  FRST_NM_left    LST_NM_left CITY_NM_left    FULL_NM_left    MIN_CITY_left   MATCH_NAME  FRST_NM_right   LST_NM_right    CITY_NM_right   UNIQUE_ID   FULL_NM_right   MIN_CITY_right
0   0.167755    0_left  0_right Doe John    New York    doe john    new doe john    Doe John    New York    N1  doe john    new
1   0.081166    1_left  1_right Obama   Barack  New York    barack obama    new barack hussein obama    Obama   Barack Hussein  New York    N2  barack hussein obama    new

这里有一些examples。

如果你非要坚持使用fuzzy_wuzzy.process.extractOne，你可以匹配并从匹配的名称中找到unique_id，如：

def match1(x, choices, scorer, cutoff):
        match = process.extractOne(x['FULL_NM'], choices=choices.loc[choices['MIN_CITY'] == x['MIN_CITY'],'FULL_NM'], 
                                   scorer=scorer, 
                                   score_cutoff=cutoff)
        if match:
            return choices[choices['FULL_NM'] == 'doe john'].UNIQUE_ID[0]