如何根据条件在python中合并？

Question

我想知道是否有可能通过给出“if”语句来合并两个数据帧。 例如

df

number account_name  classification
     1        name         named
     2        place        partner
     3        animal       class
     4        thing        territory
     5        dog          home

df1

account_name   Number   country
name            1         xx
place           2         xy
animal          7         yz
dog             8         zx

我正在寻找如下代码

pd.merge(df,df1, on= 'account_name') if df[number] == df1[number]

结果应该是这样的

number  account_name  classification  number Country
     1        name         named          1      xx
     2        place        partner        2      xy

我也试过 lambda 函数，代码是

x['nn'] = x.apply(lambda y: pd.merge(df, df1, on = 'account_name')  if df[number] == df1[number] else 1, axis=1)

Answer 1

看来您需要在参数on 中添加列：

df = pd.merge(df,df1, on= ['account_name', 'number']) 
print (df)
   number account_name classification country
0       1         name          named      xx
1       2        place        partner      xy

但如果列名不同，则在merge 中使用参数left_on 和right_on：

df = pd.merge(df, 
              df1, 
              left_on= ['account_name', 'number'], 
              right_on= ['account_name', 'Number']) 
print (df)
   number account_name classification  Number country
0       1         name          named       1      xx
1       2        place        partner       2      xy