Question

Count   Month   Fruit
1       Mar     Apple
2       Apr     Kiwi
4       Jun     Orange
8       Dec     Kiwi
12      Nov     Kiwi
4       Oct     Melon

使用

counts = ou['Fruit'].value_counts().to_frame()

我得到了

Apple:  1 
Kiwi:   3 
Orange: 1 
Melon:  1

我尝试了类似的东西

counts = ou['Fruit'].where("Kiwi").value_counts()

怎么可能只计算猕猴桃？输出只是 3或新西兰人：3

Answer 1

我重新创建你的数据 - 然后给你'Kiwi'的出现次数。如果你想要总数，那么只需将count（）改为sum（）

import pandas as pd

d={'count':[1,2,4,8,12,4],
'Month':['Mar','Apr','Jun','Dec','Nov','Oct'],
  'Fruit':['Apple','Kiwi','Orange','Kiwi','Kiwi','Melon']}
df=pd.DataFrame(d)
df[df.Fruit=='Kiwi'].count()

Answer 2

如果需要Kiwi的长度仅限True个值：

print (ou['Fruit'] == 'Kiwi')
0    False
1     True
2    False
3     True
4     True
5    False
Name: Fruit, dtype: bool

print ((ou['Fruit'] == 'Kiwi').sum())
3

同样，但有点复杂：

print (ou['Fruit'].value_counts())

Kiwi      3
Melon     1
Orange    1
Apple     1
Name: Fruit, dtype: int64

counts = ou['Fruit'].value_counts().loc['Kiwi']
print (counts)
3

Pandas value_count其中行名称

2 个答案: