合并2个数据框

Question

I have 2 dataframe

for ex:

df1:

seq_id1     seq_id2
seq1_A      seq2_B
seq2_A      seq3_B
seq4_A      seq9_B
seq9_A      seq9_B
etc

and another dataframe such

df2:

sequences
seq2_A
seq9_A

and keep only in the first dataframe, the row where the ID in the dataframe is present, here it would be:

newdataframe merged:

seq_id1     seq_id2
seq2_A      seq3_B
seq9_A      seq9_B

Thanks for your help :)

here. are the dataframe= First one with only 60 rows : df1 second one with with all seq ID: df2 Here the columns ["#qseqid'"] in the first df has to match with the restricted df2 in the column ["seq2_id"]

Answer 1

I believe need for match column seq_id1 with df2['sequences'] use isin with boolean indexing :

df1[df1['seq_id1'].isin(df2['sequences'])]

Or:

df = pd.merge(df1, df2, left_on='seq_id1', right_on='sequences')

If need match both columns of df1 :

df1[df1.isin(df2['sequences']).any(axis=1)]