python - 使用 pandas.read_csv 从 URL 读取压缩的 CSV 文件时出错

Question

我正在尝试使用 pandas.read_csv 从 IPython 笔记本中的 URL(在本例中为 GitHub 原始 URL)读取 bz2 压缩的 CSV 文件，但我得到以下信息错误:

Python 无法从打开的文件句柄读取 bz2。

我做了一些研究，但我似乎无法弄清楚出了什么问题。我尝试过手动解压缩 bz2 文件，我知道它们没有损坏或损坏，而且我也知道 URL 的格式正确 - 如果我将它们输入浏览器，它就会正确下载文件。

这是我的 IPython 笔记本中的代码:

import pandas, bz2, urllib2
datafiles = {}
for filename in csvData['Filename']:
    csvUrl = 'https://raw.github.com/hawkw/traverse/master/data/' + filename
    try:
        datafiles[filename] = pandas.read_csv(csvUrl, compression='bz2')
        print (datafiles[filename])
    except Exception as e:
        print("Caught error \"{error}\" at {url}".format(error=e, url=csvUrl))

输出:

Caught error "Python cannot read bz2 from open file handle" at https://raw.github.com/hawkw/traverse/master/data/-Users-hawk-_2014-02-05.csv.bz2
Caught error "Python cannot read bz2 from open file handle" at https://raw.github.com/hawkw/traverse/master/data/-Users-Owner_2014-02-05.csv.bz2
Caught error "Python cannot read bz2 from open file handle" at https://raw.github.com/hawkw/traverse/master/data/-Users-will_2014-02-05.csv.bz2
Caught error "Python cannot read bz2 from open file handle" at https://raw.github.com/hawkw/traverse/master/data/-Users-hawk_2014-02-06.csv.bz2
Caught error "Python cannot read bz2 from open file handle" at https://raw.github.com/hawkw/traverse/master/data/-Users-hawk-Documents_2014-02-06.csv.bz2
Caught error "Python cannot read bz2 from open file handle" at https://raw.github.com/hawkw/traverse/master/data/-home-w-weismanm_2014-02-05.csv.bz2
Caught error "Python cannot read bz2 from open file handle" at https://raw.github.com/hawkw/traverse/master/data/-home-w-weismanm_2014-02-06.csv.bz2

有人知道我做错了什么吗？

编辑:我尝试像这样使用 urllib2 打开文件，正如 @edchum 建议的那样:

datafiles = {}

for filename in csvData['Filename']:

    url = 'https://raw.github.com/hawkw/traverse/master/data/' + filename

    try:
        response = urllib2.urlopen(url)
    except HTTPError as e:
        print ("Caught HTTPError", e)
    else:
        try:
            datafiles[filename] = pandas.read_csv(response, compression='bz2')
            print (datafiles[filename])
        except Exception as e:
            print("Caught error \"{0}\" at {1}".format(e,url))

但它仍然不起作用，失败并出现同样的错误。附带说明一下，pandas.read_csv() 表示它可以从文档中的 URL 打开文件。

Answer 1

如果由于某种原因您绝对不能简单地下载文件，并且必须不断从远程源(不是很近)中提取它们，那么如果需要，您可以在内存中完成所有操作:

>>> import pandas as pd
>>> import io
>>> import urllib2
>>> import bz2
>>> 
>>> url = "https://github.com/hawkw/traverse/blob/master/data/-Users-hawk_2014-02-06.csv.bz2?raw=true"
>>> raw_data = urllib2.urlopen(url).read()
>>> data = bz2.decompress(raw_data)
>>> df = pd.read_csv(io.BytesIO(data))
>>> df.head()
                                                path  st_mode    st_ino  \
0  /Users/hawk/Library/minecraft/bin/minecraft/mo...    33261  59612469   
1  /Users/hawk/Library/Application Support/Google...    16832  91818463   
2  /Users/hawk/Library/Caches/Metadata/Safari/His...    33188  95398522   
3  /Users/hawk/Documents/Minecraft1.6.4/assets/so...    33188  90620503   
4  /Users/hawk/Library/Caches/Metadata/Safari/His...    33188  96129272   

     st_dev  st_nlink  st_uid  st_gid  st_size    st_atime    st_mtime  \
0  16777219         1     501      20     2626  1370201925  1366983504   
1  16777219         3     501      20      102  1391697388  1384638452   
2  16777219         1     501      20    36758  1389032348  1389032363   
3  16777219         1     501      20    12129  1387000073  1384114141   
4  16777219         1     501      20      170  1390545751  1390545751   

     st_ctime  
0  1368736019  
1  1384638452  
2  1389032363  
3  1384114141  
4  1390545751  

[5 rows x 11 columns]

您想要传递适当的encoding参数的位置。