删除CSV输出中的'b'标志 [英] Remove 'b' flag in CSV output

问题描述

我正在尝试将输出写入Python 3.4中的CSV文件，但是CSV文件始终包含'b'标志.例如，b'The text output1'，b'The text output2'，...我想知道是否有一种方法可以摆脱'b'标志.我了解这在Python 2.X中不是问题.

I am trying to write the outputs to a CSV file in Python 3.4 but the CSV file always contains 'b' flags. For example, b'The text output1', b'The text output2',... I am wondering if there is a way to get rid of the 'b' flags. I understand that this is not an issue in Python 2.X.

这是我使用的代码

with open('test.csv', 'w') as f:
    writer = csv.DictWriter(f, ['field'], extrasaction='ignore')
    writer.writeheader()
    test_text = mongo.test.find({'text': text})
    for t in test_text
        writer.writerow({i:v.encode('utf') for i,v in t.items()})

非常感谢

------更新-------------

------Updates-----------

非常感谢Tim Pietzcker，John Zwinck和Warren Weckesser提供有用的评论和答案.根据沃伦的建议，如果我将代码更改为

Thanks very much for Tim Pietzcker, John Zwinck, and Warren Weckesser providing helpful comments and answers. Per Warren's suggestions, if I change my codes to

import csv

data = [chr(0x03d5) + 'oo', 'b' + chr(0x0101) + 'r']

with open('test.csv', 'w') as f:
    writer = csv.writer(f)
    for item in data:
        writer.writerow([item])

我会收到错误消息

UnicodeEncodeError: 'charmap' codec can't encode character '\u03d5' in position 0: character maps to <undefined>

如果我将代码更改为

import csv

data = [chr(0x03d5) + 'oo', 'b' + chr(0x0101) + 'r']

with open('test.csv', 'w') as f:
    writer = csv.writer(f)
    for item in data:
        writer.writerow([item.encode('utf')])

我将获得带有'b'标志的输出

I will get outputs with 'b' flags

b'\xcf\x95oo'
b'b\xc4\x81r'

关于这种情况如何发生以及如何解决该问题的任何想法?再次感谢.

Any thoughts on how this is happening and how I might be able to fix it? Thanks again.

------更新2 -----------

------Updates 2-----------

非常感谢沃伦的解决方案.以下代码有效！

Thanks very much for Warren's solution. The following codes worked!

import csv

data = [chr(0x03d5) + 'oo', 'b' + chr(0x0101) + 'r']

with open('test.csv', 'w', encoding='utf8') as f:
    writer = csv.writer(f)
    for item in data:
        writer.writerow([item])

推荐答案

不要自己对字符串进行显式编码.让作者来照顾它.例如，这段代码:

Don't explicitly encode the strings yourself; let the writer take care of it. For example, this code:

import csv

data = [chr(0x03d5) + 'oo', 'b' + chr(0x0101) + 'r']

with open('test.csv', 'w') as f:
    writer = csv.writer(f)
    for item in data:
        writer.writerow([item])

写入文件

ϕoo
bār

具有UTF-8编码(至少在我的系统上是这样，其中locale.getpreferredencoding(False)返回'UTF-8').要使编码明确，可以在调用中将编码设置为open:

with UTF-8 encoding (at least it does on my system, where locale.getpreferredencoding(False) returns 'UTF-8'). To make the encoding explicit, you can set the encoding in the call to open:

    with open('test.csv', 'w', encoding='utf8') as f:

如果最后一行更改为writer.writerow([item.encode('utf')])(将字符串转换为bytes)，则会产生

If the last line is changed to writer.writerow([item.encode('utf')]) (which converts the strings to bytes), it produces

b'\xcf\x95oo'
b'b\xc4\x81r'

在您的示例中，尝试更改此行:

In your example, try changing this line:

        writer.writerow({i:v.encode('utf') for i,v in t.items()})

对此:

        writer.writerow(t)

然后，如果可行，您可以将其替换:

Then if that works, you could replace this:

    for t in test_text
        writer.writerow({i:v.encode('utf') for i,v in t.items()})

使用

    writer.writerows(test_text)

这篇关于删除CSV输出中的'b'标志的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！