Question

我正在使用for循环合并3个数据帧，但仅返回最后一个df

我已经阅读了python-guide的陷阱和Python Pocket Reference。我了解问题出在“默认值”

请忽略下面的缩进问题。该功能否则定义正确

def hkmultiday(code, date1asstring, date2asstring):
    x = pd.bdate_range(date1asstring, date2asstring)

#there are 2 business dates between the 2 input dates

df2=pd.DataFrame([[datetime.datetime.now(),0,0,0,0,0,0,0]],columns=['date','open','high','low','close','volume','barCount','average'])


#i created an empty dataframe for "append" function.  using the append function allows me to organize the final dataframes by decreasing dates

for date in x.date:
               y=datetime.datetime(year=date.year,month=date.month,day=date.day,hour=16,minute=0,second=1)
        df2=hkday(code,y).append(df2, ignore_index=True)

#hkday is a custom function defined outside hkmultiday.  It returns a dataframe for one-day stock data.  

    return df2

预期：空数据框+第1天数据框+第2天数据框

实际：空数据框+第2天数据框

我怀疑它与“默认值”有关，并且我需要在上面的代码中的某处添加“ df2 = df2”。但是我不知道在哪里。在hkday.append（）中添加df2 = df2会产生错误。谢谢

从循环返回所有值

0 个答案: