Question

我尝试使用df.to_csv（）将数据帧写入.csv。由于某种原因，它只写了最后一个值（最后一个自动收报机的数据）。它通过一系列代码（乌龟，所有代码都在第一列）读取，并为每个代码发出价格数据。我可以毫无问题地打印所有数据，但似乎无法写入.csv。知道为什么吗？感谢

input_file = pd.read_csv("turtle.csv", header=None)

for ticker in input_file.iloc[:,0].tolist():
    data = web.DataReader(ticker, "yahoo", datetime(2011,06,1),     datetime(2016,05,31))
    data['ymd'] = data.index
    year_month = data.index.to_period('M')
    data['year_month'] = year_month
    first_day_of_months = data.groupby(["year_month"])["ymd"].min()
    first_day_of_months = first_day_of_months.to_frame().reset_index(level=0)
    last_day_of_months = data.groupby(["year_month"])["ymd"].max()
    last_day_of_months = last_day_of_months.to_frame().reset_index(level=0)
    fday_open = data.merge(first_day_of_months,on=['ymd'])
    fday_open = fday_open[['year_month_x','Open']]
    lday_open = data.merge(last_day_of_months,on=['ymd'])
    lday_open = lday_open[['year_month_x','Open']]

    fday_lday = fday_open.merge(lday_open,on=['year_month_x'])
    monthly_changes = {i:MonthlyChange(i) for i in range(1,13)}

    for index,ym, openf,openl in fday_lday.itertuples():
            month = ym.strftime('%m')
            month = int(month)
            diff = (openf-openl)/openf
            monthly_changes[month].add_change(diff)

    changes_df = pd.DataFrame([monthly_changes[i].get_data() for i in monthly_changes],columns=["Month","Avg Inc.","Inc","Avg.Dec","Dec"])

    CSVdir = r"C:\Users\..."
    realCSVdir = os.path.realpath(CSVdir)

    if not os.path.exists(CSVdir):
        os.makedirs(CSVdir)

    new_file_name = os.path.join(realCSVdir,'PriceData.csv')
    new_file = open(new_file_name, 'wb')

    new_file.write(ticker)
    changes_df.to_csv(new_file)

Answer 1

使用a代替wb，因为它会在循环的每次迭代中覆盖数据。对于打开文件的不同模式，请参阅here。

数据框到.csv - 只写最后一个值 - Python / Pandas

1 个答案: