First.isin(["Meredith","Summer"])].loc[:,"Phone"]###Modify & Removedf.First[df.First < "B"] = "Unicorn" y = df[1:] y = df["A1002":] y = df[df.index != "A1001"] df = df[pd.notnull(df.A)] #去掉A中nan的行 df = df.set_index("A") #改变index df["B"] = ...