我有一个CSV文件,列名大写。我正在使用csv.dictreader读取数据,但需要小写的列名。
我在这里找到了这段代码Accessing csv header white space and case insensitive
import csv
class DictReaderInsensitive(csv.DictReader):
# This class overrides the csv.fieldnames property.
# All fieldnames are without white space and in lower case
@property
def fieldnames(self):
return [field.strip().lower() for field in super(DictReaderInsensitive, self).fieldnames]
def __next__(self):
# get the result from the original __next__, but store it in DictInsensitive
dInsensitive = DictInsensitive()
dOriginal = super(DictReaderInsensitive, self).__next__()
# store all pairs from the old dict in the new, custom one
for key, value in dOriginal.items():
dInsensitive[key] = value
return dInsensitive
class DictInsensitive(dict):
# This class overrides the __getitem__ method to automatically strip() and lower() the input key
def __getitem__(self, key):
return dict.__getitem__(self, key.strip().lower())
我的问题是当我用
运行时datafile = open(self.ifs_data_file,'rU')
csvDict = DictReaderInsensitive(datafile)
for row in csvDict:
print row
#self.db.ifs_data.insert(**row)
#self.db.commit()
我收到此错误
Traceback (most recent call last):
File "D:\Development\python\supplier_review\supplier_review.py", line 239, in update_ifs_data
for row in csvDict:
File "D:\Python27_5\lib\csv.py", line 103, in next
self.fieldnames
File "D:\Development\python\supplier_review\supplier_review.py", line 288, in fieldnames
return [field.strip().lower() for field in super(DictReaderInsensitive, self).fieldnames]
TypeError: must be type, not classobj
答案 0 :(得分:9)
您可以将文件的第一行小写,然后再将其传递给DictReader
:
import csv
import itertools
def lower_first(iterator):
return itertools.chain([next(iterator).lower()], iterator)
with open(ifs_data_file, 'rU') as datafile:
csvDict = csv.DictReader(lower_first(datafile))
for row in csvDict:
print row
答案 1 :(得分:7)
DictReader
是一个旧式对象,因此super()
在这里根本不起作用。您需要直接访问父类中的property
对象。在Python 2中,您希望覆盖.next()
方法,而不是.__next__()
:
class DictReaderInsensitive(csv.DictReader):
# This class overrides the csv.fieldnames property.
# All fieldnames are without white space and in lower case
@property
def fieldnames(self):
return [field.strip().lower() for field in csv.DictReader.fieldnames.fget(self)]
def next(self):
return DictInsensitive(csv.DictReader.next(self))
演示:
>>> example = '''\
... foo,Bar,BAZ
... 42,3.14159,Hello world!'''.splitlines()
>>> csvDict = DictReaderInsensitive(example)
>>> row = next(csvDict)
>>> print row
{'bar': '3.14159', 'foo': '42', 'baz': 'Hello world!'}
>>> row['BAZ']
'Hello world!'
答案 2 :(得分:2)
对于更简单的方法,您只需在访问字典之前更新DictReader.fieldnames属性,如:
>>> f = open('example-x-y-time.csv', 'rb')
>>> reader = csv.DictReader(f)
>>> reader.fieldnames
['Latitude', 'Longitude', 'Date']
>>> print next(reader)
{'Latitude': '44.8982391', 'Date': '2004-07-12', 'Longitude': '-117.7791061'}
>>> reader.fieldnames = [name.lower() for name in reader.fieldnames]
>>> print next(reader)
{'latitude': '44.6637001', 'date': '1964-04-03', 'longitude': '-123.5997009'}