calculate day of the year from 15minute timeseries data-CodePudding

I want a column with day of year. How do I calculate day of the year with 15-minute interval data which are resampled to daily entries. The following code produces day of year for each 15-minute interval but I only want day of year for each day.

I also tried to resample "Time" but that does not work. Anyone have any suggestions as to how I might get day of year?

df = pd.read_csv("D:/time-series.csv")

df = df.set_index(pd.DatetimeIndex(df["Time"]))
day_of_year = pd.DatetimeIndex(df["Time"]).dayofyear
#time = df["Time"].resample("24H")
pp = df["precip"].resample("24H").sum()

Current result

day_of_year
Int64Index([182, 182, 182, 182, 182, 182, 182, 182, 182, 182,
            ...
            366, 366, 366, 366, 366, 366, 366, 366, 366, 366],
           dtype='int64', name='Time', length=30720)

Expected result

day_of_year
Time
2017-07-01     182
2017-07-02     183
2017-07-03     184
2017-07-04     185
2017-07-05     186
              ... 
2020-12-27     362
2020-12-28     363
2020-12-29     364
2020-12-30     365
2020-12-31     366

CodePudding user response：

Typing this in the blind as I don't have your data file:

df = pd.read_csv("D:/time-series.csv", parse_dates=["Time"], index_col="Time")
pp = df["precip"].resample("24H").sum()
day_of_year = pp.index.dayofyear

If you want a dataframe:

day_of_year = pd.DataFrame({
    "day_of_year": pp.index.dayofyear
}, index=pp.index)