How to extract rows in a dataframe that do not exist in another

Question

I have two dataframes:

all_data:

              AID       VID  Freq
0        00016A3E  0127C661     1
1        00016A3E  0C05DA5D     2
2        0001         


        

Answer 1

This worked for me:

merged = all_data.merge(subset, how='left', indicator=True)
print(merged[merged['_merge']=='left_only'])

After the merge, you can filter by the _merge with left_only value.