Python dictreader - CSV列名を小文字にするには？

Question

大文字の列名を持つCSVファイルがあります。私はcsv.dictreaderを使ってデータを読んでいますが、小文字の列名が必要です。

私が見つかりました。ここでは、このコード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()) 

私の問題は、私は

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() 

でこれを実行すると、私はこのエラー

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 

Answer 1

DictReaderを得ることにある古いスタイルですオブジェクトなので、super()はまったく動作しません。親クラスのpropertyオブジェクトに直接アクセスする必要があります。

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)) 

デモ：

>>> 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!' 

Answer 2

あなたはDictReaderにそれを渡す前に、ファイルの最初の行を小文字できます

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  

のPython 2では、あなたは .next()方法、ない .__next__()を上書きしたいです

Answer 3

はるかに簡単な方法として、次のように辞書にアクセスする前にDictReader.fieldnames属性を更新するだけです。

>>> 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'}