Question

require "openssl"
require "nokogiri"
require 'csv'
require "open-uri"
OpenSSL::SSL::VERIFY_PEER = OpenSSL::SSL::VERIFY_NONE
$n=0

#~ Open_Page
page = ('http://www.residentadvisor.net/dj/aguycalledgerald/tracks?sort=mostcharted')
html = Nokogiri::HTML(open(page))

#~ Array
names= []
html.css('a').each do |x|
  names<< x.text.strip.gsub(/\t/,'')
  names.delete('RA on YouTube')
  names.delete('Login')
  names.delete('Register')
  names.delete('Resident Advisor')
  names.delete('Submit')
  names.delete('Listings')
  names.delete('Clubs')
  names.delete('News')
  names.delete('Reviews')
  names.delete('Features')
  names.delete('Films')
  names.delete('Submit event')
  names.delete('Artists')
  names.delete('Photos')
  names.delete('DJ Charts')
  names.delete('Labels')
  names.delete('Podcasts')
  names.delete('Search')
  names.delete('Top 1000')
  names.delete('Top 100')
  names.delete('Local')
  names.delete('Favourites')
  names.delete('Create an artist profile')
  names.delete('Reviews')
  names.delete('Features')
  names.delete('A') 
  names.delete('B') 
  names.delete('C') 
  names.delete('D') 
  names.delete('E') 
  names.delete('F') 
  names.delete('G') 
  names.delete('H') 
  names.delete('I') 
  names.delete('J') 
  names.delete('K') 
  names.delete('L') 
  names.delete('M') 
  names.delete('N') 
  names.delete('O') 
  names.delete('P') 
  names.delete('Q') 
  names.delete('R') 
  names.delete('S') 
  names.delete('T') 
  names.delete('U') 
  names.delete('V') 
  names.delete('W') 
  names.delete('X') 
  names.delete('Y') 
  names.delete('Z') 
  names.delete('0-9') 
  names.delete('RA') 
  names.delete('About') 
  names.delete('Advertise') 
  names.delete('Jobs') 
  names.delete('RA In Residence') 
  names.delete('Ticketing FAQ') 
  names.delete('Sell tickets on RA') 
  names.delete('Privacy') 
  names.delete('Terms') 
  names.delete('RA is also available in Japanese. æ—¥æœ¬ç‰ˆ') 
  names.delete('Download the RA Guide') 
  names.delete('RA on Twitter') 
  names.delete('RA on Facebook') 
  names.delete('RA on Google+') 
  names.delete('RA on Instagram') 
  names.delete('RA on Soundcloud')
  names.delete('Biography')
  names.delete('Events')
  names.delete('Tracks')
  names.delete('RA News')
  names.delete('RA Editorial')
  names.delete('Remixes')
  names.delete('Solo productions')
  names.delete('Collaborations')
  names.delete('Laboratory Instinct')
  names.delete('Highgrade Records')
  names.delete('Bosconi')
  names.delete('!K7')
  names.delete('Perlon')
  names.delete('Beatstreet')
  names.delete('Title')
  names.delete('Label')
  names.delete('Release Date')
  names.delete('51 chartings')
  puts names
end

#~ To_CSV
for $n in 0..names.count do 
  CSV.open('Most_Charted.csv','a+') do |csv|
    csv  << [names[$n]]

  end
end

创建一个CSV文件：

PositiveNoise (Carl Craig remix)  System 7 & Guy Called Gerald  A-Wave 22 chartings

Voodoo Ray (Shield Re-Edit)   A Guy Called Gerald   18 chartings

Falling (D. Digglers Cleptomania remix)   Tom Clark & Benno Blome feat.
  A Guy Called Gerald   18 chartings

How Long Is Now   A Guy Called Gerald   14 chartings

Groove Of The Ghetto  A Guy Called Gerald   12 chartings

Voodoo Ray  A Guy Called Gerald   10 chartings

Falling (D Diggler's Rescue remix)  Tom Clark & Benno Blome feat. A
Guy Called Gerald   9 chartings

等等。

如何只将前5首歌曲名称传递给CSV文件？

Answer 1

确保在禁用SSL检查时知道自己在做什么。

您可以为曲目列表找到更好的选择器，因此您不需要所有这些“删除”。这些曲目都在ul.tracks

之内

然后我建议你把整个事情变成一个班级。所以你可以封装行为。然后不要使用$全局变量。不需要，通常是不良代码的标志。

以下是一份工作样本：

require "openssl"
require "nokogiri"
require 'csv'
require "open-uri"
OpenSSL::SSL::VERIFY_PEER = OpenSSL::SSL::VERIFY_NONE

class Tracklist

  def initialize(url)
    @url = url
  end

  def parse(top = nil)
    html = Nokogiri::HTML(open(url))
    result = []

    html.css('ul.tracks li').each do |node|
      title = node.css('div.title a:nth-child(1)').first
      result << title.text if !title.nil?
      break if top && result.length == top
    end

    result
  end

  private

  attr_reader :url

end


list = Tracklist.new("https://www.residentadvisor.net/dj/aguycalledgerald/tracks?sort=mostcharted")
p list.parse(5)

如果您需要有关曲目的更多信息，那么您可以在parse方法中的循环中提取更多详细信息。

此代码在达到top后停止解析。之后，您可以根据需要构建CSV。

如何仅将前五个曲目传递给CSV文件？

1 个答案: