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
标签：顺序,删除,df,dataframe,merge,result,query,left From： https://www.cnblogs.com/tiansz/p/16785392.html