python - Pandas value_count where 行名称

Question

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

与

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

我明白

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

我尝试过类似的事情

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

怎么可能只计算奇异果呢？ 输出只是 3 或新西兰人:3

Answer 1

我重新创建您的数据 - 然后为您提供“Kiwi”出现的次数。如果你想要总数，只需将 count() 更改为 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()