Ruby Autovivification

Question

我一直试图在ruby中使用autovivification进行简单的记录合并:

2009-08-21|09:30:01|A1|EGLE|Eagle Bulk Shpg|BUY|6000|5.03
2009-08-21|09:30:35|A2|JOYG|Joy Global Inc|BUY|4000|39.76
2009-08-21|09:30:35|A2|LEAP|Leap Wireless|BUY|2100|16.36
2009-08-21|09:30:36|A1|AINV|Apollo Inv Cp|BUY|2300|9.15
2009-08-21|09:30:36|A1|CTAS|Cintas Corp|SELL|9800|27.83
2009-08-21|09:30:38|A1|KRE|SPDR KBW Regional Banking ETF|BUY|9200|21.70
2009-08-21|09:30:39|A1|APA|APACHE CORPORATION|BUY|5700|87.18
2009-08-21|09:30:40|A1|FITB|Fifth Third Bancorp|BUY|9900|10.86
2009-08-21|09:30:40|A1|ICO|INTERNATIONAL COAL GROUP, INC.|SELL|7100|3.45
2009-08-21|09:30:41|A1|NLY|ANNALY CAPITAL MANAGEMENT. INC.|BUY|3000|17.31
2009-08-21|09:30:42|A2|GAZ|iPath Dow Jones - AIG Natural Gas Total Return Sub-Index ETN|SELL|6600|14.09
2009-08-21|09:30:44|A2|CVBF|Cvb Finl|BUY|1100|7.64
2009-08-21|09:30:44|A2|JCP|PENNEY COMPANY, INC.|BUY|300|31.05
2009-08-21|09:30:36|A1|AINV|Apollo Inv Cp|BUY|4500|9.15

所以例如我希望A1 AINV BUY 9.15的记录总共有6800.这是使用自动修复的完美问题.继承我的代码:

#!/usr/bin/ruby

require 'facets'


h = Hash.autonew

File.open('trades_long.dat','r').each do |line|

        @date,@time,@account,@ticker,@desc,@type,amount,@price = line.chomp.split('|')
        if @account != "account"
           puts "#{amount}"
           h[@account][@ticker][@type][@price] += amount
         end

    #puts sum.to_s
end

问题是无论我如何总结h [@account] [@ ticker] [@ type] [@ price]中的值,它给了我这个错误:

6000
/usr/local/lib/ruby/gems/1.9.1/gems/facets-2.7.0/lib/core/facets/hash/op_add.rb:8:in `merge': can't convert String into Hash (TypeError)
    from /usr/local/lib/ruby/gems/1.9.1/gems/facets-2.7.0/lib/core/facets/hash/op_add.rb:8:in `+'
    from ./trades_consolidaton.rb:13
    from ./trades_consolidaton.rb:8:in `each'
    from ./trades_consolidaton.rb:8

我尝试过使用不同的"autovivification"方法,没有结果.这不会发生在perl!autofvification会知道你想要做什么.ruby似乎没有这个功能.

所以我的问题是,我如何简单地"整合"ruby中的记录.具体来说,我如何获得以下内容的总数:

H [@account] [@股票] [@类型] [@价格]

非常感谢您的帮助!!

只是为了澄清格伦的解决方案.这将是完美的,除了它给出(在ruby 1.9中使用标准CSV库的一些修改:

CSV.foreach("trades_long.dat", :col_sep => "|") do |row| 
     date,time,account,ticker,desc,type,amount,price = *row 
     records[[account,ticker,type,price]] += amount 
end

给出以下错误:

TypeError: String can't be coerced into Fixnum
    from (irb):64:in `+'
    from (irb):64:in `block in irb_binding'
    from /usr/local/lib/ruby/1.9.1/csv.rb:1761:in `each'
    from /usr/local/lib/ruby/1.9.1/csv.rb:1197:in `block in foreach'
    from /usr/local/lib/ruby/1.9.1/csv.rb:1335:in `open'
    from /usr/local/lib/ruby/1.9.1/csv.rb:1196:in `foreach'
    from (irb):62
    from /usr/local/bin/irb:12:in `<main>'

Answer 1

我同意乔纳斯的观点,你(和萨姆)正在使它变得比它需要的更复杂,但我认为即使他的版本太复杂了.我只是这样做:

require 'fastercsv'
records = Hash.new(0)
FasterCSV.foreach("trades_long.dat", :col_sep => "|") do |row|
  date,time,account,ticker,desc,type,amount,price = row.fields
  records[[account,ticker,type,price]] += amount.to_f
end

现在,您有一个哈希值,其中包含帐户,代码,类型和价格的每个唯一组合的总金额.