如何使用csv.DictReader跳过标题前行？

Question

我想csv.DictReader从文件中推断出字段名称。文档说：
“如果省略fieldnames参数，则csvfile第一行中的值将用作字段名。” ，但在我的情况下，第一行包含标题，第二行包含名称。

我无法next(reader)按照Python
3.2的要求在csv.DictReader中跳过一行，
因为在初始化读取器时发生了字段名分配（否则我做错了）。

csvfile（从Excel
2010导出，原始源）：

CanVec v1.1.0,,,,,,,,,^M
Entity,Attributes combination,"Specification Code
Point","Specification Code
Line","Specification Code
Area",Generic Code,Theme,"GML - Entity name
Shape - File name
Point","GML - Entity name
Shape - File name
Line","GML - Entity name
Shape - File name
Area"^M
Amusement park,Amusement park,,,2260012,2260009,LX,,,LX_2260009_2^M
Auto wrecker,Auto wrecker,,,2360012,2360009,IC,,,IC_2360009_2^M

我的代码：

f = open(entities_table,'rb')
try:
    dialect = csv.Sniffer().sniff(f.read(1024))
    f.seek(0)

    reader = csv.DictReader(f, dialect=dialect)
    print 'I think the field names are:\n%s\n' % (reader.fieldnames)

    i = 0
    for row in reader:
        if i < 20:
            print row
            i = i + 1

finally:
    f.close()

当前结果：

I think the field names are:
['CanVec v1.1.0', '', '', '', '', '', '', '', '', '']

所需结果：

I think the field names are:
['Entity','Attributes combination','"Specification Code Point"',...snip]

我意识到只删除第一行并继续进行是很方便的，但是我正在尝试尽可能地就地读取数据并尽量减少人工干预。

Answer 1

我从itertools使用过islice。我的标题位于重要序言的最后一行。我已经通过了序言，并使用hederline作为字段名：

with open(file, "r") as f:
    '''Pass preamble'''
    n = 0
    for line in f.readlines():
        n += 1
        if 'same_field_name' in line: # line with field names was found
            h = line.split(',')
            break
    f.close()
    f = islice(open(i, "r"), n, None)

    reader = csv.DictReader(f, fieldnames = h)