Python Nested Loop Doesn't Loop

I'm a python beginner and I can't make my loop loop. Here's the case : I've got two csv files (event logs). First on is called bd8result.csv with 4 or 5 lines structured like these

Solution 1:

After one iteration of looping over reader2, reader1 is exhausted by its for loop and raises StopIteration and won't return anything in the successive loops.

You should get a new instance of csv.reader in every iteration:

withopen('result_'+ namefile +'.csv', 'rb') as master1:
    forrowin csv.reader(master1):
        target =row[1]
        lecteur =row[5]
        epoch_ref =int(row[-1])
        withopen('epoch_'+ namefile +'.csv', 'rb') as hosts1:
            for row2 in csv.reader(hosts1):
                epoch1 =int(row2[-1])
                lecteur1 = row2[5]
                withopen('result_scout'+ namefile +'.csv', 'a') as results1:
                     if epoch1 > (epoch_ref - ecart) and epoch1 < (epoch_ref + ecart) and lecteur1 == lecteur:
                        writer1 = csv.writer(results1)
                        writer1.writerow([target]+[sys.argv[1]]+row2)
                        results1.close()

From the documentation:

csv.reader(csvfile)

Return a reader object which will iterate over lines in the given csvfile. csvfile can be any object which supports the iterator protocol and returns a string each time its next() method is called.

This implies that after the reader raises StopIteration it will be exhausted just like an exhausted generator.