all rows in df1 that are NOT in df2

Question

I have a df (df1) that looks like:

df1 = pd.DataFrame([
        [\'YYZ\', \'SFO\', 1],
        [\'YYZ\', \'YYD\', 1],
        [\'YYZ\', \'EWR\', 1],
        [\'Y         


        

Answer 1

Just ask the question straight in plain English, hmm I mean in plain pandas. "Select all rows in df1 that are not in df2" translates to:

df1[~df1.isin(df2).all(axis=1)]
Out[127]: 
  city1 city2  val
2   YYZ   EWR    1
3   YYZ   DFW    1
4   YYZ   LAX    1
5   YYZ   YYC    1