Question

正在学习创建一个用户-用户协作推荐系统，在这里我借助Python：MySql_Connector从MySql数据库中读取隐式数据。使用“购买”数据，我试图创建一个用户*项目评分矩阵，为此，我要将行（700,000行）透视成带有熊猫的列。当我对整个数据框运行数据透视时，出现以下错误。

“ ValueError：未堆叠的DataFrame太大，导致int32溢出”

import mysql.connector
import pandas as pd
import numpy as np
from mysql.connector import errorcode
def readData():
    try:
        mySQLConnection = mysql.connector.connect(host='localhost',
                                             database='testdb',
                                             user='user',
                                             password='pwd')
        cursor = mySQLConnection.cursor(prepared=True)
        sql_select_query = """""" #Removed the select query
        cursor.execute(sql_select_query)
        record = cursor.fetchall()
        return record
    except mysql.connector.Error as error:
        print("Failed to get record from database: {}".format(error))
    finally:
        # closing database connection.
        if (mySQLConnection.is_connected()):
            cursor.close()
            mySQLConnection.close()
            print("connection is closed")

data = readData()
df = pd.DataFrame(data,columns=['user_id','product_id','purchase_count'])
data_pivot = pd.pivot_table(df,index=['user_id'],columns=df['product_id'])
#print(data_pivot.to_string())

python_version：3.6 操作系统：Win7 内存：16GB pandas_version：0.24.2

用熊猫将行透视成列

0 个答案: