{"id":3675,"date":"2023-07-16T05:09:27","date_gmt":"2023-07-16T05:09:27","guid":{"rendered":"https:\/\/statorials.org\/nl\/pandas-tellen-specifieke-rijen-op\/"},"modified":"2023-07-16T05:09:27","modified_gmt":"2023-07-16T05:09:27","slug":"pandas-tellen-specifieke-rijen-op","status":"publish","type":"post","link":"https:\/\/statorials.org\/nl\/pandas-tellen-specifieke-rijen-op\/","title":{"rendered":"Hoe specifieke rijen in panda's toe te voegen (met voorbeelden)"},"content":{"rendered":"

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U kunt de volgende methoden gebruiken om de som van specifieke rijen in een pandas DataFrame te vinden:<\/span><\/p>\n

Methode 1: Voeg specifieke rijen toe per index<\/strong><\/span><\/p>\n

 #sum rows in index positions 0, 1, and 4<\/span>\ndf. iloc<\/span> [[0, 1, 4]]. sum<\/span> ()\n<\/strong><\/pre>\n
 Methode 2: Voeg specifieke rijen toe per label<\/strong><\/span><\/p>\n
 #sum rows with index labels 'A', 'B', and 'E'<\/span>\ndf. loc<\/span> [['A', 'B', 'E']]. sum<\/span> () \n<\/strong><\/pre>\n
 De volgende voorbeelden laten zien hoe u elke methode in de praktijk kunt gebruiken met de volgende panda’s DataFrame:<\/span><\/p>\n
 import<\/span> pandas as<\/span> pd<\/span>\n\n#createDataFrame\n<\/span>df = pd. DataFrame<\/span> ({' points<\/span> ': [28, 17, 19, 14, 23, 26, 5],\n                   ' rebounds<\/span> ': [5, 6, 4, 7, 14, 12, 9],\n                   ' assists<\/span> ': [10, 13, 7, 8, 4, 5, 8]})\n\n#set indexes\n<\/span>df = df. set_index<\/span> ([pd. Index<\/span> (['A', 'B', 'C', 'D', 'E', 'F', 'G'])])\n\n#view DataFrame\n<\/span>print<\/span> (df)\n\n   points rebound assists\nA 28 5 10\nB 17 6 13\nC 19 4 7\nD 14 7 8\nE 23 14 4\nF 26 12 5\nG 5 9 8<\/strong><\/pre>\n
 Voorbeeld 1: Som van specifieke rijen per index<\/strong><\/span><\/h2>\n
 De volgende code laat zien hoe u de waarden van rijen met indexwaarden 0, 1 en 4 voor elke kolom in het DataFrame kunt optellen:<\/span><\/p>\n
 #sum rows in index positions 0, 1, and 4<\/span>\ndf. iloc<\/span> [[0, 1, 4]]. sum<\/span> ()\n\npoints 68\nrebounds 25\nassists 27\ndtype: int64<\/span><\/span><\/strong><\/pre>\n
 Uit het resultaat kunnen we zien:<\/span><\/p>\n