in `block in <top (required)>': undefined method `match' for nil:NilClass (NoMethodError) 你的意思是？抓住。红宝石和 CSV答案

【问题标题】：in `block in <top (required)>': undefined method `match' for nil:NilClass (NoMethodError) Did you mean? catch. Ruby and CSVin `block in <top (required)>': undefined method `match' for nil:NilClass (NoMethodError) 你的意思是？抓住。红宝石和 CSV
【发布时间】：2016-06-23 12:10:15
【问题描述】：

尝试使用 CSV 将链接转换为图像。运行我的代码时出现错误在block in <top (required)>': undefined methodmatch' 中为 nil:NilClass (NoMethodError) 你的意思？赶上

代码--

require 'open-uri'
require 'tempfile'
require 'uri'
require 'csv'

DOWNLOAD_DIR = "#{Dir.pwd}/BD/"
CSV_FILE = "#{Dir.pwd}/konvertera.csv"

def downloadFile(id, url, format)
  begin
   open("#{DOWNLOAD_DIR}#{id}.#{format}", "wb+") do |file|
   file << open(url).read
   puts "Successfully downloaded #{url} to #{DOWNLOAD_DIR}#{id}.#{format}"
 end
rescue
  puts "404 not found #{url}"
 end
end


CSV.foreach(CSV_FILE, headers: true, col_sep: ";") do |row|
 id = row[0]
 format = row[1].match(/BD\.(.+)$/)&.captures.first
 url = row[1].gsub ".pdf", ""
 downloadFile(id, url, format)
end

【问题讨论】：

标签： ruby csv

【解决方案1】：

CSV.foreach(CSV_FILE, headers: true, col_sep: ";") do |row|
  # ⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓
  next unless row[0] && row[1]
  # ⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑
  id = row[0]
  format = row[1].match(/BD\.(.+)$/)&.captures.first
  url = row[1].gsub ".pdf", ""
  downloadFile(id, url, format)
end

【讨论】：