我希望csv.DictReader
从文件中推断出字段名称。 The docs说“如果省略了fieldnames参数,则csvfile第一行中的值将用作字段名。”,但在我的情况下,第一行包含标题和第二行包含名称。
我无法按照Python 3.2 skip a line in csv.DictReader应用next(reader)
因为字段名称分配在初始化阅读器时发生(或者我做错了)。
csvfile(从Excel 2010导出,original source):
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()
目前的结果:
I think the field names are:
['CanVec v1.1.0', '', '', '', '', '', '', '', '', '']
期望的结果:
I think the field names are:
['Entity','Attributes combination','"Specification Code Point"',...snip]
我意识到简单地删除第一行并继续进行是有利的,但我正试图尽可能地在原地阅读数据,并尽量减少人工干预。
答案 0 :(得分:12)
在f.seek(0)
之后,插入:
next(f)
在初始化DictReader
之前将文件指针前进到第二行。
答案 1 :(得分:1)
我使用了itertools的islice。我的标题是一个大序言的最后一行。我已通过序言并使用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)