daily_to_10day.py

import pandas as pd
from math import ceil
for region in ['CherryEleanor', 'DonPedro', 'Hetchy']:
    
    # define input and output paths
    inpath = 'baserun/{}/statvar.csv'.format(region)
    outpath = 'baserun/{}/10day.csv'.format(region)
    
    # read in the original csv
    df = pd.read_csv(inpath, index_col=0, parse_dates=True)
    
    # add indices
    df['year'] = [dt.year for dt in df.index]
    df['month'] = [dt.month for dt in df.index]
    df['10day'] = [min(ceil(dt.day/10),3) for dt in df.index]
    df.reset_index(drop=True, inplace=True)
    df.set_index(['year', 'month', '10day'], inplace=True)
    
    # aggregate by 10-day period to sum and/or mean and add to new dataframe
#     dfsum = df.groupby(by=['year', 'month', '10day']).sum()
    dfmean = df.groupby(by=['year', 'month', '10day']).mean()
    out = pd.DataFrame(index=dfmean.index)
    out['runoff'] = dfmean['basin_cfs']
    out['swe'] = dfmean['basin_pweqv']
    
    # write results
    out.to_csv(outpath)