from datetime import timedelta
import itertools

def dates_posteriors1(data_ini, ndies):
    i = 0
    while True:
        yield data_ini + timedelta(days=i)
        i += ndies
        
def dates_posteriors2(data_ini, ndies):
    it1 = itertools.count(0, ndies)
    it2 = map(lambda n: data_ini + timedelta(days=n), it1)
    return it2


# tria la solució que vols provar
dates_posteriors = dates_posteriors2