How to convert days in days of year(365)?

Question

I have a dataframe and I want a function to convert the days in days of year(365). Thanks in advance.!!

d_w_data.drop(['kwh',  'time', 'month', 'dewptm', 'hum', 'wspdm', 'cos(hour)', 'sin(hour)'], inplace=True, axis=1)

d_w_data

Out[55]:
                         year   day     index1                aptemp      maptemp      mtempm   tempm      hour_to_rad
2012-04-12 14:00:00     2012    12  2012-04-12 14:00:00     17.574044   14.483582   15.508494   19.510000   3.665191
2012-04-12 15:00:00     2012    12  2012-04-12 15:00:00     17.769016   14.483582   15.508494   19.600000   3.926991
2012-04-12 16:00:00     2012    12  2012-04-12 16:00:00     17.532051   14.483582   15.508494   19.488235   4.188790
2012-04-12 17:00:00     2012    12  2012-04-12 17:00:00     16.975478   14.483582   15.508494   18.690000   4.450590
2012-04-12 18:00:00     2012    12  2012-04-12 18:00:00     16.520319   14.483582   15.508494   17.566667   4.712389
2012-04-12 19:00:00     2012    12  2012-04-12 19:00:00     15.481347   14.483582   15.508494   16.778125   4.974188
2012-04-12 20:00:00     2012    12  2012-04-12 20:00:00     15.361154   14.483582   15.508494   16.275862   5.235988
2012-04-12 21:00:00     2012    12  2012-04-12 21:00:00     15.084252   14.483582   15.508494   15.584211   5.497787

Yes the dataframe is pandas and I want to convert days in days of year(1-365). I want to do a load forecasting.Thank you!!

Answer 1

If you parse your dates to struct_time you'll get days of year as an attribute.

>>>import time
>>>time.strptime("18 Jun 15", "%d %b %y")
time.struct_time(tm_year=2015, tm_mon=6, tm_mday=18, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=3, tm_yday=169, tm_isdst=-1)

So:

>>>import time
>>>time.strptime("18 Jun 15", "%d %b %y").tm_yday
169

Answer 2

You don't have to leave pandas to do this.

dti = pd.date_range('05-01-1990', '05-31-1990')
dti.dayofyear

returns

array([121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133,
       134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146,
       147, 148, 149, 150, 151], dtype=int32)