如何使用Pandas添加python中未列出的数据帧循环组合

如何将不在列表“a”中的组合添加到数据框行

我想使用

contains（）

或

isin（）

预期结果 不存在的列表将使用默认值0填充值的平均值

a = [["a1","b1"],["a2","b2"],["a3","b3"],["a4","b4"],["a5","b5"]]

df = pd.DataFrame({'A' : ["a1","a2","a3","a4"], 'B' : ["b1","b2","b3", "b4"] , 'mean' : ["13.4","12,1","10.0","11.5"]})

---

创建

DataFrame

构造函数并转换为原始值，然后通过指定列删除重复项，最后通过

fillna

替换缺少的值：

pd.DataFrame({'A' : ["a1","a2","a3","a4","a5"], B' : ["b1","b2","b3", "b4","b5"] ,'mean' : ["13.4","12,1","10.0","11.5", "0"]}) 

与

合并的另一个想法是：

a = [["a1","b1"],["a2","b2"],["a3","b3"],["a4","b4"],["a5","b5"]]

df1 = df.append(pd.DataFrame(a,columns=['A','B'])).drop_duplicates(subset=['A','B']).fillna(0)

print (df1)
    A   B  mean
0  a1  b1  13.4
1  a2  b2  12,1
2  a3  b3  10.0
3  a4  b4  11.5
4  a5  b5     0

df1 = pd.DataFrame(a, columns=['A','B']).merge(df, how='left').fillna(0)