写入多个csv文件而不在每行打开/关闭 - Python 3.5

Question

我有一个大的csv文件，我正在检查每一行的第二列，然后在另一个csv文件中写入此行。我使用Python 3.5
我的csv文件如下所示：

node_1,type,node_2  
154555,intermediary,154587
1545877,president,145888
4575885,intermediary,4785774

我需要为每种类型提供不同的csv文件（中间人，总统......）

import csv
import os.path

i = 0
list = []
with open('all_edges.csv', 'r') as edges:
    edges_reader = csv.reader(edges)
    for row in edges_reader:
        if row[1] not in list:
            list.append(row[1])
        while row[1] != list[i]:
            i += 1
        if i != 0:
            if not os.path.exists(r'./edges%d.csv' %i):
                with open('edges%d.csv' %i, "w+", newline='') as new_edges:
                    edges_writer = csv.writer(new_edges)
                    edges_writer.writerow(["node_1", "rel_type", "node_2"])
            with open('edges%d.csv' %i, "a+", newline='') as new_edges:
                edges_writer = csv.writer(new_edges)
                edges_writer.writerow(row)
            i = 0

您对如何避免在每一行打开和关闭输出文件有任何建议。

由于