使用python熊貓，找到列中按幾列分組的元素的計數

如何查找使用python熊貓分組的幾列中元素的計數？使用python熊貓，找到列中按幾列分組的元素的計數

我有以下csv文件結構：

'Country'  'City'  'Year' 'Month' 'Value' 'Street_Code' 
USA   New York 1971  jan  0.0  1 
USA   New York 1971  feb  23.5  1 
USA   New York 1971  mar  10.2  1 
USA   Florida  1971  jan  0.0  1 
USA   Florida  1971  feb  0.0  1 
USA   Florida  1971  mar  0.0  1 
USA   New York 1971  jan  0.0  2 
USA   New York 1971  feb  15.0  2 
USA   New York 1971  mar  7.6  2 
USA   Florida  1971  jan  0.0  2 
USA   Florida  1971  feb  0.0  2 
USA   Florida  1971  mar  2.3  2

欲通過分組'Country'，'City'，'Year' & 'Street Code'計數在'value'零（0.0）的數量。

我已經嘗試過目前爲止;

import pandas as pd 
data = pd.read_csv('country_details.csv') 
count_data = data[data['Value'] == 0.0] # I'm filtering the data. I don't think this is the right way of doing it 
grouped = count_data.groupby(['Country','Year','Month','Street_Code']) # I'm stuck here

來源

2013-04-23 richie

並您的數據得到正確地解析read_csv？ – elyase 2013-04-23 14:16:38

是的。沒有問題。 – richie 2013-04-23 14:17:40

如果你的數據被'read_csv'正確解析，爲什麼你有一個名爲''0''的列？我以爲它會是'data [data ['Value'] == 0]'。 – DSM 2013-04-23 14:19:13

您的過濾幾乎是正確的，但您需要引用列名稱，在這種情況下，'值'。

嘗試：

import pandas as pd 
import StringIO 

csv = StringIO.StringIO("""Country,City,Year,Month,Value,Street_Code 
USA,NewYork,1971,jan,0.0,1 
USA,NewYork,1971,feb,23.5,1 
USA,NewYork,1971,mar,10.2,1 
USA,Florida,1971,jan,0.0,1 
USA,Florida,1971,feb,0.0,1 
USA,Florida,1971,mar,0.0,1 
USA,NewYork,1971,jan,0.0,2 
USA,NewYork,1971,feb,15.0,2 
USA,NewYork,1971,mar,7.6,2 
USA,Florida,1971,jan,0.0,2 
USA,Florida,1971,feb,0.0,2 
USA,Florida,1971,mar,2.3,2""") 

data = pd.read_csv(csv) 

datasub = data[data['Value'] == 0.0] 

print datasub.groupby(['Country','Year','Month','Street_Code'])['Value'].count() 

Country Year Month Street_Code 
USA  1971 feb 1    1 
         2    1 
       jan 1    2 
         2    2 
       mar 1    1

來源

2013-04-23 14:19:33

使用python熊貓，找到列中按幾列分組的元素的計數

回答

相關問題