g.py

list1 = ['1\n', '00:04:11,588 --> 00:04:13,920\n', 'Nurse Evelyn! Nurse Evelyn!\n', '\n', '2\n', '00:04:15,024 --> 00:04:17,788\n', 'I have a message for you. In English!\n', '\n', '3\n', '00:04:35,345 --> 00:04:37,575\n']

def get_strings_position_in_list(astring, alist, position):
    for position, string in enumerate(alist):
        if alist[position].find(astring) != -1:
            yield position

for g in get_strings_position_in_list(" --> ", list1, 0):
    print(g)


### next(g) output 1, and then next(g) it still be 1, It should be 5