如何将 output 从 Python 循环保存到 CSV 文件？

Question

我想将 output 从以下 Python 循环保存到 CSV

ticker_list = ['GBX', 'AYI', 'SMPL', 'BSET']

from yahoofinancials import YahooFinancials as yf

yahoo_financials = yf(ticker_list)

price = yahoo_financials.get_historical_price_data('2019-07-02', '2019-07-02', 'daily')

df = pd.DataFrame(price)


def get_price():
    df1 = pd.DataFrame()
    for i in ticker_list:
        df1_i = pd.DataFrame(df[i]['prices'])
        df1_i['ticker'] = i
        df1 = df1.append(df1_i)

    df1.to_csv(r'price_20190702.csv')

我想将所有四个代码的价格信息保存到单个 CSV 文件中。 但是，当我调用def get_price()时，没有保存 CSV 文件。

Answer 1

您可以 append 数据帧：

import pandas as pd
from yahoofinancials import YahooFinancials as yf

TICKER_LIST = ['GBX', 'AYI', 'SMPL', 'BSET']
yahoo_financials = yf(TICKER_LIST)
price = yahoo_financials.get_historical_price_data('2019-07-02', '2019-07-02', 'daily')

df = pd.DataFrame()
for t in TICKER_LIST:
    df = df.append(price[t], ignore_index=True)
df.to_csv('price_20190702.csv', index=False)

Output：

eventsData,firstTradeDate,id,isPending,prices,timeZone
{},"{'formatted_date': '1994-07-14', 'date': 774172800}",1d15620256001562025600,0.0,[],{'gmtOffset': -14400}
{},"{'formatted_date': '2001-12-03', 'date': 1007370000}",1d15620256001562025600,0.0,[],{'gmtOffset': -14400}
{},"{'formatted_date': '2017-07-05', 'date': 1499241600}",1d15620256001562025600,0.0,[],{'gmtOffset': -14400}
{},"{'formatted_date': '1980-03-17', 'date': 322131600}",1d15620256001562025600,0.0,[],{'gmtOffset': -14400}

Answer 2

您可以使用打开

例如：

while True:
   data = 'Changes every time'
   with open('t.csv','a') as f:
      wr = csv.writer(f)
      wr.writerow(data)