我有14个CSV文件，每个文件有100列，我要做的是从每个文件中提取第一列并将其复制到单个csv文件中。我必须为每100列这样做（例如，下一步是将每个文件的第二列放入csv文件中）。
我之前尝试过的是下面的代码，该代码非常适合提取一列，但是我想将其放入循环中，以便立即获得100个文件，我该怎么做？
import csv
import itertools as IT
filenames = ['Sul-v1.csv', 'Sul-v2.csv','Sul-v3.csv', 'Sul-v4.csv', 'Sul-v5.csv', 'Sul-v6.csv', 'Sul-v7.csv', 'Sul-v8.csv', 'Sul-v9.csv', 'Sul-v10.csv', 'Sul-v11.csv', 'Sul-v12.csv', 'Sul-v13.csv', 'Sul-v14.csv']
handles = [open(filename, 'rb') for filename in filenames]
readers = [csv.reader(f, delimiter=',') for f in handles]
with open('combined.csv', 'wb') as h:
writer = csv.writer(h, delimiter=',', lineterminator='\n', )
for rows in IT.izip_longest(*readers, fillvalue=['']*2):
combined_row = []
for row in rows:
row = row[:1] # select the columns you want
if len(row) == 1:
combined_row.extend(row)
else:
combined.extend(['']*2)
writer.writerow(combined_row)
for f in handles:
f.close()
谢谢！