Python2.7:数据清洗的list index out of range问题

Question

from csv import reader

data_rdr = reader(open('mn.csv','rb'))
header_rdr = reader(open('mn_headers.csv','rb'))

data_rows = [d for d in data_rdr]
header_rows = [h for h in header_rdr]

bad_rows = []

for h in header_rows:
    if h[0] not in data_rows[0]:
        bad_rows.append(h)

for h in bad_rows:
    header_rows.remove(h)

print len(header_rows)

 Traceback (most recent call last):
  File "/home/sewell-hoo/datafiles/test_listindex.py", line 12, in <module>
    if h[0] not in data_rows[0]:
IndexError: list index out of range

正在读《python数据处理》一书，这是第7章第2小节的内容：
处理2个CSV文件，却一直提示List index out of range，实在是想不到哪里错了。
请忽略图中配图的文件'mn_header_update.csv',两者是一个文件

Answer 1

目测你的header_rows中有[]这样的空数据，你试着打印下：
for h in header_rows:
if h == []:
print 'h is []'