MongoDB - 使用 mongoexport 时出现意外的字符编码答案

【问题标题】：MongoDB - Unexpected character encodings when using mongoexportMongoDB - 使用 mongoexport 时出现意外的字符编码
【发布时间】：2019-02-14 01:21:38
【问题描述】：

我在一个集合上使用 mongoexport，该集合包含以 utf8 编码的外来字符以及带有 mongoexport 似乎正在编码的字符的字段（例如，'&'）。我注意到的是 mongo export 对 '&' 字符进行了 unicode 转义，但保留了 'ü' 等字符未转义。这是一个问题，因为我正在尝试使用 Python 读取这些数据，但由于发生了两种不同的编码，因此无法正确解码。

例如（mongo查询获取记录）：

db.Military_Handbooks.findOne({_id: ObjectId("5bf61c80e173a2a10b53ad39")}).PRIMARY_AUTHOR

[
  "Dürer, Albrecht",
  [
    [
      "http://ustc.ac.uk/index.php/search/cicero?tm_fulltext=&tm_field_allauthr=Dürer, Albrecht&tm_translator=&tm_editor=&tm_field_short_title=&tm_field_imprint=&tm_field_place=&sm_field_year=&f_sm_field_year=&t_sm_field_year=&sm_field_country=&sm_field_lang=&sm_field_format=&sm_field_digital=&tm_field_class=&tm_field_cit_name=&tm_field_cit_no=&order=",
      " Dürer, Albrecht"
    ]
  ]
]

运行以下 mongoexport 命令（导出为 json 时也是如此）：

mongoexport--db ustc --collection Military_Handbooks --type=csv -f=PRIMARY_AUTHOR --limit=1
"[""Dürer, Albrecht"",[[""http://ustc.ac.uk/index.php/search/cicero?tm_fulltext=\u0026tm_field_allauthr=Dürer, Albrecht\u0026tm_translator=\u0026tm_editor=\u0026tm_field_short_title=\u0026tm_field_imprint=\u0026tm_field_place=\u0026sm_field_year=\u0026f_sm_field_year=\u0026t_sm_field_year=\u0026sm_field_country=\u0026sm_field_lang=\u0026sm_field_format=\u0026sm_field_digital=\u0026tm_field_class=\u0026tm_field_cit_name=\u0026tm_field_cit_no=\u0026order="","" Dürer, Albrecht""]]]"

尝试将其读入 Python 时：

In [24]: import pandas
In [25]: c = pandas.read_csv('Military_Handbooks2.csv')
In [26]: c.at[1, 'PRIMARY_AUTHOR']
Out[26]: '["Dürer, Albrecht",[["http://ustc.ac.uk/index.php/search/cicero?tm_fulltext=\\u0026tm_field_allauthr=Dürer, Albrecht\\u0026tm_translator=\\u0026tm_editor=\\u0026tm_field_short_title=\\u0026tm_field_imprint=\\u0026tm_field_place=\\u0026sm_field_year=\\u0026f_sm_field_year=\\u0026t_sm_field_year=\\u0026sm_field_country=\\u0026sm_field_lang=\\u0026sm_field_format=\\u0026sm_field_digital=\\u0026tm_field_class=\\u0026tm_field_cit_name=\\u0026tm_field_cit_no=\\u0026order="," Dürer, Albrecht"]]]'
In [27]: c.at[1, 'PRIMARY_AUTHOR'].encode().decode('unicode-escape')
Out[27]: '["DÃ¼rer, Albrecht",[["http://ustc.ac.uk/index.php/search/cicero?tm_fulltext=&tm_field_allauthr=DÃ¼rer, Albrecht&tm_translator=&tm_editor=&tm_field_short_title=&tm_field_imprint=&tm_field_place=&sm_field_year=&f_sm_field_year=&t_sm_field_year=&sm_field_country=&sm_field_lang=&sm_field_format=&sm_field_digital=&tm_field_class=&tm_field_cit_name=&tm_field_cit_no=&order="," DÃ¼rer, Albrecht"]]]'

规格：
操作系统：Ubuntu 18.04.1 LTS
Python：3.6.7
MongoDB shell 版本 v3.6.9

【问题讨论】：

标签： python mongodb unicode character-encoding mongoexport

【解决方案1】：

最后在忽略错误的情况下重新编码文件似乎已经成功了。

def encoding():
    for fn in os.listdir('.'):
        if '2' not in fn and 'failed' not in fn and 'decode' not in fn:
            try:
                with codecs.open(fn, encoding='utf-8') as fd:
                    text = fd.read()
                    text = text.encode('Windows-1252', errors='ignore').decode('utf-8', errors='ignore')
                with codecs.open(fn[:fn.rfind('.')]+'2.csv', 'w', encoding='utf-8') as fd:
                        fd.write(text)
            except Exception as ex:
                print(ex)
                print('*'*50, '\n')

我还应该注意我链接到这篇很有帮助的帖子：how to export correctly accented words with mongoexport。

【讨论】：