大dataframe删除小dataframe，然后调整dataframe顺序

df = pd.merge(df, df1, how='left', indicator=True).query("_merge=='left_only'").drop('_merge', 1)
df = pd.merge(df, df2, how='left', indicator=True).query("_merge=='left_only'").drop('_merge', 1)

result = df1.append(df)
result = result.append(df2)

参考资料：https://blog.csdn.net/domodo2012/article/details/110705597