访问csv头空白和不区分大小写 [英] Accessing csv header white space and case insensitive

问题描述

我覆盖 csv.Dictreader.fieldnames 属性，如下所示从csv文件读取所有标题，没有空格和小写。

  import csv 
 class MyDictReader（csv.DictReader）：
 
 @property 
 def fieldnames self）：
 return [field.strip（）。lower（）for super（MyDictReader，self）.fieldnames] 
  

现在我的问题是，如何自动访问 strip（）和 lower code>查询？

这是我手动进行的操作：

  csvDict = MyDictReader（open（'csv-file.csv'，'rU'））
 
 for csvDict中的lineDict：
 query ='Column_A'.strip（）。lower（）
 print（lineDict [query]）
  

任何想法？

 根据Pedro Romano的建议，我编写了以下示例。 import csv 
 
类DictReaderInsensitive（csv.DictReader）：
＃此类覆盖csv.fieldnames属性。 
＃所有字段名都没有空格，小写字母
 
 @property 
 def fieldnames（self）：
 return [field.strip对于字段在super（DictReaderInsensitive，self）.fieldnames] 
 
 def __next __（self）：
＃从原来的__next__获取结果，但存储在DictInsensitive 
 
 dInsensitive = DictInsensitive（）
 dOriginal = super（DictReaderInsensitive，self）.__ next __（）
 
＃存储来自旧的dict的所有对，在新的自定义的
 key，value in dOriginal.items（）：
 dInsensitive [key] = value 
 
 return dInsensitive 
 
 class DictInsensitive（dict）：
＃类覆盖__getitem__方法以自动剥离（）和降低输入键
 
 def __getitem __（self，key）：
 return dict .__ getitem __（self，key.strip lower（）
  

对于包含

标题的文件
$ b b

• column_A


• column_A


• Column_A


• Column_A


• ...

：

  csvDict = DictReaderInsensitive（open（'csv-file.csv'，'rU'））
 
 for lineDict in csvDict：
 print（lineDict ['Column_A']）＃或
 print（lineDict ['Column_A']）＃或
 print（lineDict ['column_a']） ＃all都返回相同的
  

I'm overriding the csv.Dictreader.fieldnames property like the following to read all headers from csv files without white space and in lower case.

import csv
class MyDictReader(csv.DictReader):

    @property
    def fieldnames(self):
        return [field.strip().lower() for field in super(MyDictReader, self).fieldnames]

Now my question is, how can I access the fieldnames with automatically strip() and lower() the query?

This is, how I do it manually:

csvDict = MyDictReader(open('csv-file.csv', 'rU'))

for lineDict in csvDict:
    query = ' Column_A'.strip().lower()
    print(lineDict[query])

Any ideas?

解决方案

Based on Pedro Romano's suggestion I coded the following example.

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())

For a file containing headers like

• "column_A"
• " column_A"
• "Column_A"
• " Column_A"
• ...

you can access the columns like this:

csvDict = DictReaderInsensitive(open('csv-file.csv', 'rU'))

for lineDict in csvDict:
    print(lineDict[' Column_A']) # or
    print(lineDict['Column_A']) # or
    print(lineDict[' column_a']) # all returns the same

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