Python - Pandas 資料框中的分組列
要對 Pandas 資料框中的列進行分組,請使用 groupby()。首先,讓我們建立一個 Pandas 資料框 -
dataFrame = pd.DataFrame( { "Car": ["Audi", "Lexus", "Audi", "Mercedes", "Audi", "Lexus", "Mercedes", "Lexus", "Mercedes"], "Reg_Price": [1000, 1400, 1100, 900, 1700, 1800, 1300, 1150, 1350] } )
現在,讓我們按照 Car 列進行分組 -
res = dataFrame.groupby("Car")
分組後,我們將使用函式來查詢分組車輛名稱的平均註冊價格 (Reg_Price) -
res.mean()
這會根據 Car 列計算註冊價格的平均值。
示例
以下是程式碼 -
import pandas as pd # dataframe with one of the columns as Reg_Price dataFrame = pd.DataFrame( { "Car": ["Audi", "Lexus", "Audi", "Mercedes", "Audi", "Lexus", "Mercedes", "Lexus", "Mercedes"], "Reg_Price": [1000, 1400, 1100, 900, 1700, 1800, 1300, 1150, 1350] } ) print"DataFrame...\n",dataFrame # grouped according to Car res = dataFrame.groupby("Car") print"\nMean of Registration Price grouped according to Car names...\n",res.mean()
輸出
這將生成以下輸出 -
DataFrame... Car Reg_Price 0 Audi 1000 1 Lexus 1400 2 Audi 1100 3 Mercedes 900 4 Audi 1700 5 Lexus 1800 6 Mercedes 1300 7 Lexus 1150 8 Mercedes 1350 Mean of Registration Price grouped according to Car names... Reg_Price Car Audi 1266.666667 Lexus 1450.000000 Mercedes 1183.333333
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