使用 YAML 文件中的随机 key/value

Question

我正在尝试使用 YAML 文件中的随机键值对，如下所示：

'user_agents':
  'Mozilla': '5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)'
  'Mozilla': '5.0 (compatible; Yahoo! Slurp; http://help.yahoo.com/help/us/ysearch/slurp)'
  'Mozilla': '5.0 (iPhone; U; CPU iPhone OS 3_0 like Mac OS X; en-us) AppleWebKit/528.18 (KHTML, like Gecko) Version/4.0 Mobile/7A341 Safari/528.16'
  'Mozilla': '4.0 (compatible; MSIE 6.0; Windows NT 5.1)'

使用这个脚本：

require 'mechanize'
require 'yaml'

info = YAML.load_file('test-rand.yml')
@user_agent = info['user_agents'][info.keys.sample]

agent = Mechanize.new
agent.user_agent = @user_agent
if @user_agent.nil?
  puts "The user agent is nil"
else
  puts "Using: #{@user_agent}"
end

然而，虽然运行这个脚本我一直在获取 The user agent is nil，你如何从 YAML 文件中随机提取 key/value？

我也试过了@user_agent = info['user_agents'][info[rand(values.size)]]

Answer 1

How do you pull a random key/value from a YAML file?

您当前的 yaml 文件包含相同的键 Mozilla。 ruby 将 yaml 文件转换为哈希。在 ruby 散列中只能包含唯一键。所以你的 yaml 文件看起来像：

=> {"user_agents"=>{"Mozilla"=>"4.0 (compatible; MSIE 6.0; Windows NT 5.1)"}}

带有唯一键的 yml 文件：

'user_agents':
  'Mozilla_1': '5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)'
  'Mozilla_2': '5.0 (compatible; Yahoo! Slurp; http://help.yahoo.com/help/us/ysearch/slurp)'
  'Mozilla_3': '5.0 (iPhone; U; CPU iPhone OS 3_0 like Mac OS X; en-us) AppleWebKit/528.18 (KHTML, like Gecko) Version/4.0 Mobile/7A341 Safari/528.16'
  'Mozilla_4': '4.0 (compatible; MSIE 6.0; Windows NT 5.1)'

Rails 控制台：

=> info = YAML.load_file('y.yml')
=> {"user_agents"=>
  {"Mozilla_1"=>"5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)",
   "Mozilla_2"=>"5.0 (compatible; Yahoo! Slurp; http://help.yahoo.com/help/us/ysearch/slurp)",
   "Mozilla_3"=>"5.0 (iPhone; U; CPU iPhone OS 3_0 like Mac OS X; en-us) AppleWebKit/528.18 (KHTML, like Gecko) Version/4.0 Mobile/7A341 Safari/528.16",
   "Mozilla_4"=>"4.0 (compatible; MSIE 6.0; Windows NT 5.1)"}}

获取随机值而不是密钥：

=> info["user_agents"]["Mozilla_#{rand(1..4)}"]
#> "5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"
=>  info["user_agents"]["Mozilla_#{rand(1..4)}"]
#> "5.0 (iPhone; U; CPU iPhone OS 3_0 like Mac OS X; en-us) AppleWebKit/528.18 (KHTML, like Gecko) Version/4.0 Mobile/7A341 Safari/528.16"
=> info["user_agents"]["Mozilla_#{rand(1..4)}"]
#> "5.0 (compatible; Yahoo! Slurp; http://help.yahoo.com/help/us/ysearch/slurp)"
=> and so on....

Answer 2

我想我找到了一个解决方案，如果有人有更好的解决方案请告诉我，我将 YAML 文件更改为只有一个 Mozilla 具有多个值：

YAML：

'user_agents':
  'Mozilla': ['5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)', '4.0 (compatible; MSIE 6.0; Windows NT 5.1)', '5.0 (iPhone; U; CPU iPhone OS 3_0 like Mac OS X; en-us) AppleWebKit/528.18 (KHTML, like Gecko) Version/4.0 Mobile/7A341 Safari/528.16', '5.0 (compatible; Yahoo! Slurp; http://help.yahoo.com/help/us/ysearch/slurp)']

然后我使用键和值将 YAML 文件分解为键值对：

info = YAML.load_file('test-rand.yml')
info['user_agents'].each do |k,v|

从那里我把值变成一个数组，对数组进行采样，并将结果保存到一个变量中，然后我创建了一个名为 @user_agent 的新散列，并给它 k 的键以及 arr_val.to_s 的值：

arr_val = v.to_a.sample
@user_agent = {k => arr_val.to_s}

完整脚本：

require 'mechanize'
require 'yaml'

info = YAML.load_file('test-rand.yml')
info['user_agents'].each do |k,v|
  arr_val = v.to_a.sample
  @user_agent = {k => arr_val.to_s}
end

agent = Mechanize.new
agent.user_agent = @user_agent
if @user_agent.nil?
  puts "The user agent is nil"
else
  puts "Using: #{@user_agent}"
end
#<= Using: {"Mozilla"=>"5.0 (iPhone; U; CPU iPhone OS 3_0 like Mac OS X; en-us) AppleWebKit/528.18 (KHTML, like Gecko) Version/4.0 Mobile/7A341 Safari/528.16"}
#<= Using: {"Mozilla"=>"5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"}
#<= Using: {"Mozilla"=>"4.0 (compatible; MSIE 6.0; Windows NT 5.1)"}

使用 YAML 文件中的随机 key/value

Using random key/value from YAML file

ruby

random

yaml

key-value