Python 平均数和加权平均数
我是新来的。 任何帮助都将不胜感激 这是我的原始数据:Python 平均数和加权平均数,python,pandas,Python,Pandas,我是新来的。 任何帮助都将不胜感激 这是我的原始数据: Feed Close Sector Market_Cap Date 2015-09-18 A 5.60 Property 50 2015-09-21 A 5.60 Property 20 2015-09-23 A 5.60 Property 30 2015-09-18 ABC 0.67 Property 50 2015-09-21 ABC 0.66 Pro
Feed Close Sector Market_Cap
Date
2015-09-18 A 5.60 Property 50
2015-09-21 A 5.60 Property 20
2015-09-23 A 5.60 Property 30
2015-09-18 ABC 0.67 Property 50
2015-09-21 ABC 0.66 Property 80
2015-09-18 DA 0.67 Mining 65
2015-09-21 KK 1.66 Mining 80
我想得到的是:
1创建一个新的列调用平均值,以计算每个提要的平均市值
2求加权平均数
This is what I want:
Feed Close Sector Market_Cap Mean Sector_WeightedAvg
Date
2015-09-18 A 5.60 Property 50 33.33 33.33/(33.33+65)
2015-09-21 A 5.60 Property 20 33.33 33.33/(33.33+65)
2015-09-23 A 5.60 Property 30 33.33 33.33/(33.33+65)
2015-09-18 ABC 0.67 Property 50 65 65/(33.33+65)
2015-09-21 ABC 0.66 Property 80 65 65/(33.33+65)
2015-09-18 DA 0.67 Mining 65 62 62/(62+80)
2015-09-21 KK 1.66 Mining 80 80 80/(62+80)
这是我当前的代码,我得到NaN:
df3= pd.DataFrame(df3)
df3['Mean'] = df3.groupby(by=['Sector'])[ Market_Cap].mean()
Feed Close Sector Market_Cap Mean
Date
2015-09-18 A 5.60 Property 50 NaN
2015-09-21 A 5.60 Property 20 NaN
2015-09-23 A 5.60 Property 30 NaN
2015-09-18 ABC 0.67 Property 50 NaN
对于加权平均代码:
df2['WeightedAverage'] =df3[ Market_Cap].value /df3['Mean'].value
我得到了一个错误:
AttributeError:“Series”对象没有属性“value”
IIUC您可以使用和表示
加权平均值
为列平均值
除以列平均值
的唯一值之和,df3
按列扇区
分组
print df3
Feed Close Sector Market_Cap
Date
2015-09-18 A 5.60 Property 50
2015-09-21 A 5.60 Property 20
2015-09-23 A 5.60 Property 30
2015-09-18 ABC 0.67 Property 50
2015-09-21 ABC 0.66 Property 80
2015-09-18 DA 0.67 Mining 65
2015-09-21 KK 1.66 Mining 80
df3['Mean'] = df3.groupby(by=['Feed'])['Market_Cap'].transform('mean')
df3['WeightedAverage'] = df3['Mean'] / df3.groupby(by=['Sector'])[ 'Mean'].transform(lambda x: sum(x.unique()))
print df3
Feed Close Sector Market_Cap Mean WeightedAverage
Date
2015-09-18 A 5.60 Property 50 33.333333 0.338983
2015-09-21 A 5.60 Property 20 33.333333 0.338983
2015-09-23 A 5.60 Property 30 33.333333 0.338983
2015-09-18 ABC 0.67 Property 50 65.000000 0.661017
2015-09-21 ABC 0.66 Property 80 65.000000 0.661017
2015-09-18 DA 0.67 Mining 65 65.000000 0.448276
2015-09-21 KK 1.66 Mining 80 80.000000 0.551724
尝试转换('sum')、平均值的组合
哪个给出错误
-什么错误?我们可以得到回溯吗?您的数据框中没有值
列,但您在code.thks Eli中引用了它,我已重新发布。应该是市值。我仍然得到了相同的错误,但不是sum(x.unique())
假设每个平均值都是唯一的值吗?如果不同部门有多个相等的平均值呢?这是可能的,但在本示例中,我采用了我的方法,因为每个部门都没有重叠的Feed
。列平均值
取决于列提要
。
In [5]: df
Out[5]:
Close Feed Market_Cap Sector
0 5.60 A 50 Property
1 5.60 A 20 Property
2 5.60 A 30 Property
3 0.67 ABC 50 Property
4 0.66 ABC 80 Property
5 0.67 DA 65 Mining
6 1.66 KK 80 Mining
In [6]: g = df.groupby(['Sector', 'Feed'])
In [7]: c = g.Market_Cap.mean()
In [8]: c
Out[8]:
Sector Feed
Mining DA 65.000000
KK 80.000000
Property A 33.333333
ABC 65.000000
Name: Market_Cap, dtype: float64
In [9]: d = c.groupby(level=0).transform('sum')
In [10]: d
Out[10]:
Sector Feed
Mining DA 145.000000
KK 145.000000
Property A 98.333333
ABC 98.333333
dtype: float64
In [11]: df['Mean'] = df.apply(lambda x: c[x.Sector, x.Feed], axis=1)
In [12]: df['Weighted_Avg'] = df.apply(lambda x: c[x.Sector, x.Feed] / d[x.Sector, x.Feed], axis=1)
In [13]: df
Out[13]:
Close Feed Market_Cap Sector Mean Weighted_Avg
0 5.60 A 50 Property 33.333333 0.338983
1 5.60 A 20 Property 33.333333 0.338983
2 5.60 A 30 Property 33.333333 0.338983
3 0.67 ABC 50 Property 65.000000 0.661017
4 0.66 ABC 80 Property 65.000000 0.661017
5 0.67 DA 65 Mining 65.000000 0.448276
6 1.66 KK 80 Mining 80.000000 0.551724