Python cкрипт неправильно ищет привязанные строки в CSV файле, почему?

Question

[Error 502]

Суть данного скрипта в том, чтобы он вывел список значений из 2 файла, соответствующих значению id из первого файла. В итоге он выводит список лишь для самого первого id, а для остальных выдает пустой список "[ ]". Причем для каждого из этих id есть соответствующие значения, пустых списков там выводиться не должно. Что я не так делаю?

posts_table = open("posts.csv")
cat_rel_table = open("category_relationship.csv")

reader_1 = csv.DictReader(posts_table)
reader_2 = csv.DictReader(cat_rel_table)

def cat_name(post_id):
    cat_list = []
    for cat in reader_2:
        if cat['post_id'] == post_id:
            cat_list.append(cat['cat_id'])
    return cat_list

for post in reader_1:
    if (post['type'] == "8" and post['status'] == "1"):
        print(post['id'], cat_name(post['id']))

Comments

[Segey K.]

Можно пару кусочков CSV что бы потестить?

[Stanislav Pugachev]

Error 502 ,
csv.DictReader(cat_rel_table) то небось переопределять нужно каждый раз
он один раз до конца дойдет (для айди 1) и дальше ничего уже возвращать не будет

[Error 502]

posts.csv

"id","type","price","new_price","from_date","to_date","parent","created_at","author","featured","template","stock","view","status","barcode"
"84","8","117","0","0000-00-00 00:00:00","0000-00-00 00:00:00","0","2017-10-12 14:37:38","1","../uploads/posts/2017/10/1-10-r-c-audi-r8-v10-compl-6v.jpg","0","10","0","2",
"85","8","28","0","0000-00-00 00:00:00","0000-00-00 00:00:00","266","2017-10-12 17:41:45","1","../uploads/posts/2017/10/0011543346227-a.jpg","0","10","0","2",
"86","8","13","0","0000-00-00 00:00:00","0000-00-00 00:00:00","266","2017-10-19 10:38:06","1","../uploads/posts/2017/10/81XHlhvCsJL._SL1500_.jpg","0","10","0","2",
"87","8","28","0","0000-00-00 00:00:00","0000-00-00 00:00:00","266","2017-10-19 11:03:55","4","../uploads/posts/2017/10/cat-9-inch-big-builder-l&s-shaking-machine-vehicle-dump-truck--5AE442DA.zoom.jpg","0","10","0","1","11543346210"
"88","8","28","0","0000-00-00 00:00:00","0000-00-00 00:00:00","0","2017-10-19 11:05:59","1","../uploads/posts/2017/10/pTRUCA1-22577036_alternate1_enh-z6.jpg","0","10","0","2",

category_relationship.csv

"id","type","cat_id","post_id","status"
"31","8","21","84","2"
"32","8","21","85","2"
"33","8","20","86","2"
"34","8","21","86","2"
"35","8","20","87","1"
"36","8","21","87","2"
"37","8","20","88","2"
"38","8","21","88","2"

Answer 1

[Stanislav Pugachev]

Error 502 ,

После итерации по reader_2 сделайте
reader_2.seek(0)
или перед итерацией
ну вы поняли

Comments

[Error 502]

направили в правильное русло, только не reader_2, а хендлер файла - cat_rel_table. конечно скрипт от этого стал работать медленно.