Question

我有一个查询数据库的python函数，当我不转换为数据帧时，如何将其写入csv？还是必须导入数据框并使用该功能？

返回可以很好地在我的控制台上查看结果，但是现在我想导出为csv。

任何帮助将不胜感激。

代码：

import pandas as pd
import pyodbc, os 
import datetime
from datetime import datetime
from pandas import ExcelWriter
import numpy as np


    def date(businessDate):
        con = pyodbc.connect(r'DSN='+'Stack',autocommit=True)  
        print('working')


        sql = f"""
        SELECT * FROM date 
        where businessDate = {businessDate}

        """

        df_date = pd.read_sql(sql,con)

        con.close()

        return(df_date)

Answer 1

似乎df_date = pd.read_sql(sql,con)产生一个数据帧。您可以通过运行type(df_date)进行测试。

请参见write_to_csv()下的函数，该函数与具有date()功能的df_date.to_csv()基本上相同。在运行write_to_csv()之前，请确保csv文件已经存在，因为此函数只会写入该文件，而不创建它。

import pandas as pd
import pyodbc, os 
import datetime
from datetime import datetime
from pandas import ExcelWriter
import numpy as np


def date(businessDate):
    con = pyodbc.connect(r'DSN='+'Stack',autocommit=True)  
    print('working')
    sql = f""" 
    SELECT * FROM date 
    where businessDate = {businessDate}
    """
    df_date = pd.read_sql(sql,con)
    con.close()
    return(df_date)

path = "C:\\Users\\path\\to\\your\\folder\\file.csv"

def write_to_csv(businessDate):
    con = pyodbc.connect(r'DSN='+'Stack',autocommit=True)  
    print('working')
    sql = f""" 
    SELECT * FROM date 
    where businessDate = {businessDate}
    """
    df_date = pd.read_sql(sql,con)
    con.close()
    df_date.to_csv(path)
    return('Successfully wrote to csv')

如何使用pandas pd.read_sql导出到csv？

1 个答案: