Python Pandas Series中的数据比较

Question

这是两个数据系列，我想比较的基础上第三个。你知道吗

数据单元1：

SKU     Weight1     
1234    20
1235    30
111     40
101     23

数据单元2：

SKU     Weight2
1234    22
1235    35
111     47
101     87

标志数据：

SKU
1234     True
1235     False
111      True
101      False
Name: Date, dtype: bool

基本上基于flag\ u数据序列中的值，我需要将Weight1的值除以Weight2，反之亦然。你知道吗

对于进口：

j = flag_Data(dados_SKU1, dados_SKU1) #this generates the third series
if(j[1234]==True):
  generated_serie = data_SKU1['Weight1'][1234] / dados_SKU2['Weight2'][1234]
else:
  generated_serie = data_SKU2['Weight2'][1234] / data_SKU1['Weight1'][1234]

但它应该做的所有SKU的系列，而不仅仅是SKU 1234。你们能帮我弄清楚怎么做吗？你知道吗

Answer 1

设置
merge

df = df1.merge(df2)

    SKU  Weight1  Weight2   FLAG
0  1234       20       22   True
1  1235       30       35  False
2   111       40       47   True
3   101       23       87  False

选项1 np.where

df['division'] = np.where(df['FLAG'], df['Weight1']/df['Weight2'], df['Weight2']/df['Weight1'])

选项2
loc与fillna

df.loc[df['FLAG'], 'division'] = df.Weight1 / df.Weight2
df['division'] = df.division.fillna(df.Weight2/df.Weight1)

选项3 mask与fillna

df['division'] = (df.Weight1 / df.Weight2.mask(~df.FLAG)).fillna(df.Weight2/df.Weight1)

所有结果：

    SKU  Weight1  Weight2   FLAG  division
0  1234       20       22   True  0.909091
1  1235       30       35  False  1.166667
2   111       40       47   True  0.851064
3   101       23       87  False  3.782609

Answer 2

你可以用np.哪里为此：

result = np.where(flag_Data,
                  data_SKU1['Weight1']/data_SKU2['Weight2'],
                  data_SKU2['Weight2']/data_SKU1['Weight1'])