数据库风格的DataFrame加入/合并merge/join  2018/12/31 1.函数 pd.merge(left, right, how='inner', on=None, left_on=None, right_on=None,left_index=False, right_index=False, sort=True,suffixes=('_x', '_y'),copy=True

# 实例6：indicator添加分类到输出df1 = pd.DataFrame({'no': [10, 11], 'name':['Tom', 'Bob']})df2 = pd.DataFrame({'no': [11, 12],'weight':[20, 20]})pd.merge(df1, df2, on='no', how='outer', indicator=True) #添加分类

# 实例5.1：validate检查重复键left = pd.DataFrame({'A' : [11,12], 'B' : [13, 13]}) #B列重复数字right = pd.DataFrame({'A' : [14,15,16], 'B': [13,13,13]}) #B列重复数字left1 = pd.DataFrame({'A' : [11,12],

# 实例4：重叠值列# suffixes参数:字符串列表的元组，重叠列名后缀left = pd.DataFrame({'k': ['K0', 'K1', 'K2'], 'v': [1, 2, 3]})right = pd.DataFrame({'k': ['K0', 'K0', 'K3'], 'v': [4, 5, 6]})result = pd.merge(left, right, on=