Pass a list to .loc on a #Python #Pandas series, and get a series back:
s = pd.Series([10, 20, 30], index=list('abc'))
s.loc[['a']] # series, a:10
s.loc[['a', 'b']] # series, a:10, b:20
s.loc[['a', 'a']] # series, a:10 twice!
s.loc[['b', 'a']] # series, b:20, a:10








