Pandas join dataframes by multiple key [duplicate]
You need to use the merge function for joining tables, for your case, since you have multiple data frames to join, you can put them into a list and then use the reduce from functools to merge them one by one:
import pandas as pdfrom functools import reducereduce(lambda x, y: pd.merge(x, y, on = ['Window', 'Label']), [df1, df2, df3])# Window Label FeatA FeatB FeatC# 0 123 1 h d d# 1 123 2 f s c
you can use combine_first:
In[44]:df.combine_first(df1).combine_first(df2)[['Window','Label','FeatA','FeatB','FeatC']]Out[44]: Window Label FeatA FeatB FeatC0 123 1 h d d1 123 2 f s cor you can use merge:
In[30]:df.merge(df1,on=['Window','Label']).merge(df2,on=['Window','Label'])Out[30]: Window Label FeatA FeatB FeatC0 123 1 h d d1 123 2 f s c