Python：从CSV文件提取每日/每小时余额

Question

I have a long file which in particular has these two columns:

   Balance     Time
   1000.01     2015-08-23 19:53:23
   1235.21     2015-08-23 17:32:42
    394.33     2015-08-22 23:32:12
    534.45     2015-08-22 13:44:12
    235.21     2015-08-22 13:22:51

How can I write to a list/vector the last balance of the day (eventually the hour HH:59:59) for all the rows? Perhaps using SQLite?

UPDATE

I found a solution once extracted an array with times dates and balance bal from the csv file but I wonder if there is a less ugly way to do it. Maybe using pandas.

    import datetime as dt
    delta=dt.timedelta(hours=1)            
    new_date=dt.datetime.strptime(start_date, "%Y-%m-%d %H:%M:%S")+delta
    for i in range(len(bal)):
        if dt.datetime.strptime(dates[i], "%Y-%m-%d %H:%M:%S")>new_date:
            hours_diff=int((dt.datetime.strptime(dates[i], "%Y-%m-%d %H:%M:%S")-new_date).total_seconds()/3600)
            while dt.datetime.strptime(dates[i], "%Y-%m-%d %H:%M:%S")>new_date:
                hourly_time.append(dt.datetime.strftime(new_date,"%Y-%m-%d %H:%M:%S"))
                new_date+=delta
                hourly_bal.append(hourly_bal[-1])
            hourly_bal[-1]=bal[i-1]
    hourly_time.append(dt.datetime.strftime(new_date,"%Y-%m-%d %H:%M:%S"))
    hourly_bal.append(bal[-1])

Answer 1

Use pandas - it's great for handling time series data.

Assuming the output you want is something like this?

   Balance     Time                   LastBalance
   1000.01     2015-08-23 19:53:23    235.21
   1235.21     2015-08-23 17:32:42    235.21
    235.21     2015-08-22 17:32:42    -