用 Python 读取 UTF8 CSV 文件 [英] Reading a UTF8 CSV file with Python

问题描述

我正在尝试使用 Python(仅限法语和/或西班牙语字符)读取带有重音字符的 CSV 文件.基于 csvreader 的 Python 2.5 文档 (http://docs.python.org/library/csv.html)，我想出了以下代码来读取 CSV 文件，因为 csvreader 仅支持 ASCII.

I am trying to read a CSV file with accented characters with Python (only French and/or Spanish characters). Based on the Python 2.5 documentation for the csvreader (http://docs.python.org/library/csv.html), I came up with the following code to read the CSV file since the csvreader supports only ASCII.

def unicode_csv_reader(unicode_csv_data, dialect=csv.excel, **kwargs):
    # csv.py doesn't do Unicode; encode temporarily as UTF-8:
    csv_reader = csv.reader(utf_8_encoder(unicode_csv_data),
                            dialect=dialect, **kwargs)
    for row in csv_reader:
        # decode UTF-8 back to Unicode, cell by cell:
        yield [unicode(cell, 'utf-8') for cell in row]

def utf_8_encoder(unicode_csv_data):
    for line in unicode_csv_data:
        yield line.encode('utf-8')

filename = 'output.csv'
reader = unicode_csv_reader(open(filename))
try:
    products = []
    for field1, field2, field3 in reader:
        ...

以下是我尝试阅读的 CSV 文件的摘录:

Below is an extract of the CSV file I am trying to read:

0665000FS10120684,SD1200IS,Appareil photo numérique PowerShot de 10 Mpx de Canon avec trépied (SD1200IS) - Bleu
0665000FS10120689,SD1200IS,Appareil photo numérique PowerShot de 10 Mpx de Canon avec trépied (SD1200IS) - Gris
0665000FS10120687,SD1200IS,Appareil photo numérique PowerShot de 10 Mpx de Canon avec trépied (SD1200IS) - Vert
...

即使我尝试编码/解码为 UTF-8，我仍然收到以下异常:

Even though I try to encode/decode to UTF-8, I am still getting the following exception:

Traceback (most recent call last):
  File ".Test.py", line 53, in <module>
    for field1, field2, field3 in reader:
  File ".Test.py", line 40, in unicode_csv_reader
    for row in csv_reader:
  File ".Test.py", line 46, in utf_8_encoder
    yield line.encode('utf-8', 'ignore')
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 68: ordinal not in range(128)

我该如何解决这个问题?

How do I fix this?

推荐答案

.encode 方法应用于 Unicode 字符串以生成字节字符串；但是你在一个字节串上调用它......错误的方式'回合！查看标准库中的 codecs 模块，特别是 codecs.open 以获得更好的通用解决方案，用于读取 UTF-8 编码的文本文件.但是，特别是对于 csv 模块，您需要传入 utf-8 数据，这就是您已经获得的数据，因此您的代码可以简单得多:

The .encode method gets applied to a Unicode string to make a byte-string; but you're calling it on a byte-string instead... the wrong way 'round! Look at the codecs module in the standard library and codecs.open in particular for better general solutions for reading UTF-8 encoded text files. However, for the csv module in particular, you need to pass in utf-8 data, and that's what you're already getting, so your code can be much simpler:

import csv

def unicode_csv_reader(utf8_data, dialect=csv.excel, **kwargs):
    csv_reader = csv.reader(utf8_data, dialect=dialect, **kwargs)
    for row in csv_reader:
        yield [unicode(cell, 'utf-8') for cell in row]

filename = 'da.csv'
reader = unicode_csv_reader(open(filename))
for field1, field2, field3 in reader:
  print field1, field2, field3 

PS:如果事实证明您的输入数据不是 utf-8，但例如在 ISO-8859-1 中，那么您确实需要一个转码"(如果您热衷于在 csv 模块级别使用 utf-8)，形式为 line.decode('whateverweirdcodec').encode('utf-8') -- 但也许你可以在上面代码的 yield 行中使用现有编码的名称，而不是 'utf-8'，因为 csv 实际上对于 ISO-8859-* 编码的字节串就可以了.

PS: if it turns out that your input data is NOT in utf-8, but e.g. in ISO-8859-1, then you do need a "transcoding" (if you're keen on using utf-8 at the csv module level), of the form line.decode('whateverweirdcodec').encode('utf-8') -- but probably you can just use the name of your existing encoding in the yield line in my code above, instead of 'utf-8', as csv is actually going to be just fine with ISO-8859-* encoded bytestrings.

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