python - 遍历一组列表，一次一个列表

Question

我有下面的代码。是否可以简化“循环”以便我不必重复语句？

topic1 = ["abc", "def"]
topic2 = ["ghi", "jkl", "mno"]
topic3 = ["pqr"]

outfile = open('topics_nodes.csv', 'w')
outfile.write("Node;Topic\n")

# The Loop
for i in topic1:
    print i
    outfile2.write(i +";1\n")
for i in topic2:
    print i
    outfile2.write(i +";2\n")
for i in topic1:
    print i
    outfile2.write(i +";3\n")

Answer 1

你可以这样做:

for index, topic_list in enumerate([topic1, topic2, topic3], 1):
    for i in topic_list:
        print i
        outfile2.write('{:d};{:d}\n'.format(i, index))