Ruby 1.9.2 - 读取和解析远程CSV [英] Ruby 1.9.2 - Read and parse a remote CSV

问题描述

我正在寻找一种方法来本地读取和解析远程CSV（托管在特定网站上）。

我在互联网上发现了几个有趣的例子使用FasterCSV，在ruby 1.9.2已被合并到CSV。我发现你可以使用gems'csv'和'open-uri'以这种方式读取远程CSV：

  require' csv'
 require'open-uri'
 
 def read（url）
 open（url）do | f | 
 f.each_line do | l | 
 CSV.parse（l）do | row | 
 puts row 
 end 
 end 
 end 
 end 
  

但是当我调用这个函数时，我得到一个异常：

 错误IOError：closed stream 
  

任何人都可以解释为什么？有什么不对吗？

更新

到目前为止我找到的最佳解决方案是这样的：

  def read（url）
 data = [] 
 begin 
 open （url）do | f | 
 data = CSV.parse f 
 end 
 rescue IOError => e 
＃静默捕获异常... 
 end 
 
返回数据
 end 
  

但它有点似乎不那么干净。我真的不喜欢默默地捕捉一个异常，不应该是...

更新2

我可以使用这两个重现错误。

  ruby​​ 1.9.2p0（2010-08-18 revision 29036）[x86_64-darwin10.4.0 ] 
  

和

  ruby​​ 1.9.2p180（2011-02-18 revision 30909）[x86_64-darwin10.7.0] 
  

这是我的 test.rb 文件的代码：

  require'rubygems'
 require'open-uri'
 require'csv'
 
 def read（url）
 data = [] 
 begin 
 open（url）do | f | 
 data = CSV.parse f 
 end 
 end 
 
输入数据
 end 
 
 read（http：// www.euribor-ebf.eu/assets/modules/rateisblue/processed_files/myav_EURIBOR_2011.csv）
  

这是 ruby​​ test.rb 命令的输出

 用户/ marzu / .rvm / rubies / ruby​​-1.9.2-p180 / lib / ruby​​ / 1.9.1 / open-uri.rb：152：在`close'：closed stream（IOError）
从/ Users /marzu/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/open-uri.rb:152:in`open_uri'
来自/Users/marzu/.rvm/rubies /ruby-1.9.2-p180/lib/ruby/1.9.1/open-uri.rb:671:in`open'
从/Users/marzu/.rvm/rubies/ruby-1.9.2- p180 / lib / ruby​​ / 1.9.1 / open-uri.rb：33：在'open'
从test.rb：8：在`read'
从test.rb： < main>'
  

我使用 rvm 1.6.9

解决方案

div>

在Mac OS X 10.6.7上，使用ruby r1.9.2，我得到与上面显示的相同的错误。但是使用以下代码来读取CSV文件适用于提供的示例URL：

  require'rubygems'
 require' open-uri'
 require'csv'
 
 def read（url）
 CSV.new（open（url），：headers =>：first_row）。线| 
 puts line 
 puts line [0] 
 puts line ['FEB11'] 
 end 
 end 
 
 read（http： /www.euribor-ebf.eu/assets/modules/rateisblue/processed_files/myav_EURIBOR_2011.csv）
  

I am looking for a way to read and parse locally a remote CSV (hosted on a particular website).

I found on the Internet a couple of interesting examples that make use of FasterCSV, that in ruby 1.9.2 has been merged into CSV. I found that you can read a remote CSV using the gems 'csv' and 'open-uri' this way:

require 'csv'
require 'open-uri'

def read(url)
  open(url) do |f|
    f.each_line do |l|
      CSV.parse(l) do |row|
        puts row
      end
    end
  end
end

But when I call this function, I get an exception:

ERROR IOError: closed stream

Anyone can explain me why? Is there anything wrong? Should I choose another approach for reading remote CSV's?

Update

The best solution I've found till now is this:

def read(url)
  data = []
  begin
    open(url) do |f|
      data = CSV.parse f
    end
  rescue IOError => e
    # Silently catch the exception ...
  end

  return data
end

but it somewhat seems not so clean. I really do not like silently catching an exception where it shouldn't be ...

Update 2

I can reproduce the error using both

ruby 1.9.2p0 (2010-08-18 revision 29036) [x86_64-darwin10.4.0]

and

ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-darwin10.7.0]

This is the code from my test.rb file:

require 'rubygems'
require 'open-uri'
require 'csv'

def read(url)
  data = []
  begin
    open(url) do |f|
      data = CSV.parse f
    end
  end

  puts data
end

read("http://www.euribor-ebf.eu/assets/modules/rateisblue/processed_files/myav_EURIBOR_2011.csv")

And this is the output of the ruby test.rb command

/Users/marzu/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/open-uri.rb:152:in `close': closed stream (IOError)
from /Users/marzu/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/open-uri.rb:152:in `open_uri'
from /Users/marzu/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/open-uri.rb:671:in `open'
from /Users/marzu/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/open-uri.rb:33:in `open'
from test.rb:8:in `read'
from test.rb:16:in `<main>'

I am using rvm 1.6.9 on Mac OS X 10.6.7.

Any suggestions?

解决方案

On Mac OS X 10.6.7, using ruby r1.9.2, I get the same error as displayed above. But using the following code to read CSV files works for the example URL provided:

require 'rubygems'
require 'open-uri'
require 'csv'

def read(url)
 CSV.new(open(url), :headers => :first_row).each do |line|
   puts line
   puts line[0]
   puts line['FEB11']
 end
end

read("http://www.euribor-ebf.eu/assets/modules/rateisblue/processed_files/myav_EURIBOR_2011.csv")

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