How would I join two dataframe based on a partial string match?

Question

I have two dataframes and want to join them based on three fields, A , B , and C . However, A and B are numeric values and I want to them match exactly in my join/merge but C is a string value and I want at least 80% match (similarity), ie if A and B have the same values in both dataframes and the value of C in the first dataframe is abcde and in the second one is abcdf I still want to consider this record in my result. How can I implement this in python?

Answer 1

You can using fuzzywuzzy

from fuzzywuzzy import fuzz

df1=pd.DataFrame({'A':[1,3,2],'B':[2,2,3],'C':['aad','aac','aad']})

df2=pd.DataFrame({'A':[1,2,2],'B':[2,2,3],'C':['aad','aab','acd']})

mergedf1=df1.merge(df2,on=['A','B'])

mergedf1['ratio']=[fuzz.ratio(x,y) for x, y in zip(mergedf1['C_x'],mergedf1['C_y'])]
mergedf1#score list here , you can cut the data frame by your own limit 
Out[265]: 
   A  B  C_x  C_y  ratio
0  1  2  aad  aad    100
1  2  3  aad  acd     67

Answer 2

I would probably merge first on only A and B, then filter out any rows that have low similarity on the C column, so something like:

result = df1.merge(df2, on=['A', 'B'])

# assuming sim is the similarity function that you created to calculate the similarity
idx = result.apply(lambda x: sim(c['C_x', 'C_y']) >= 0.8, axis=1)
result = result[idx]

Hope it helps!