got it, I may call iter(…) only once, that´s it:
it = iter(data_iter1)
first = next(it)
second = next(it)
print(first,second)
and this one makes it iterable over the length:
from itertools import cycle,islice

class myAirlineDataset(IterableDataset):
    def __init__(self, data):
        self.data = data
    def process_data(self,data):
        for x in data:
          yield x
    def get_stream(self,data):
        return cycle(self.process_data(data))
    def __len__(self):
        return len(data)
    def __iter__(self):
       return (self.get_stream(self.data.iloc[:,1]))

data=pd.read_csv('airline-passengers.csv')
dataset1=myAirlineDataset(data) 
data_iter1=torch.utils.data.DataLoader(dataset1, batch_size=1)

#for batch in islice(data_iter1,144,146):
#  print(batch)

it = iter(data_iter1)
for n in range(145):
  a=next(it)
print(a)

br