Question

我正在使用Nokogiri代码在HTML节点之间提取文本，并在我读入文件列表时收到这些错误。我没有使用简单的嵌入式HTML获取错误。我想消除或抑制警告，但不知道如何。警告出现在每个街区的末尾：

extract.rb:18: warning: already initialized constant EXTRACT_RANGES
extract.rb:25: warning: already initialized constant DELIMITER_TAGS

这是我的代码：

#!/usr/bin/env ruby -wKU
require 'rubygems'
require 'nokogiri'
require 'fileutils'

source = File.open('/documents.txt')
source.readlines.each do |line|
  line.strip!
  if File.exists? line
    file = File.open(line)

doc = Nokogiri::HTML(File.read(line))

# suggested by dan healy, stackoverflow 
# Specify the range between delimiter tags that you want to extract
# triple dot is used to exclude the end point
# 1...2 means 1 and not 2
EXTRACT_RANGES = [
  1...2
 ]

# Tags which count as delimiters, not to be extracted
DELIMITER_TAGS = [
  "h1",
  "h2",
  "h3"
]

extracted_text = []

i = 0
# Change /"html"/"body" to the correct path of the tag which contains this list
(doc/"html"/"body").children.each do |el|

  if (DELIMITER_TAGS.include? el.name)
    i += 1
  else
    extract = false
    EXTRACT_RANGES.each do |cur_range|
      if (cur_range.include? i)
        extract = true
        break
      end
    end

    if extract
      s = el.inner_text.strip
      unless s.empty?
        extracted_text << el.inner_text.strip
      end
    end
  end
end

print("\n")
puts line
print(",\n")
# Print out extracted text (each element's inner text is separated by newlines)
puts extracted_text.join("\n\n")
  end
end

Answer 1

如果代码正确缩进，则更容易注意到常量定义是在循环内完成的。

比较

source.readlines.each do |line|
  # code
  if true

# Wrongly indented code

# More
# Wrongly
# Indented
# Code
EXTRACT_RANGES = [
  1...2
 ]

# Several more pages of code
  end
end

与

source.readlines.each do |line|
  # code
  if true

    # Correctly indented code

    # What is a constant doing being defined
    # this far indented?
    # Oh no - it's in a loop!

    EXTRACT_RANGES = [
      1...2
    ]

    # Several more pages of code
  end
end

Answer 2

之前没有注意到。只需将常量移出每个块

EXTRACT_RANGES = [
  1...2
]

# Tags which count as delimiters, not to be extracted
DELIMITER_TAGS = [
 "h1",
 "h2",
 "h3"
]

source.readlines.each do |line|
 line.strip!
  if File.exists? line
    file = File.open(line)

doc = Nokogiri::HTML(File.read(line))

extracted_text = []

i = 0
# Change /"html"/"body" to the correct path of the tag which contains this list
(doc/"html"/"body").children.each do |el|

  if (DELIMITER_TAGS.include? el.name)
    i += 1
  else
    extract = false
    EXTRACT_RANGES.each do |cur_range|
      if (cur_range.include? i)
        extract = true
        break
      end
    end

    if extract
     s = el.inner_text.strip
      unless s.empty?
        extracted_text << el.inner_text.strip
      end
    end
  end
end

print("\n")
puts line
print(",\n")
# Print out extracted text (each element's inner text is separated by newlines)
puts extracted_text.join("\n\n")
  end
end

Answer 3

作为编程提示：

小心使用...与..进行范围定义。三点版本不像双点版本那样常用，并且额外的点很容易错过，使得代码难以维护。我必须有一个很好的理由使用三点。比较IRB的这些输出：

(1...2).to_a
=> [1]

VS

(1..1).to_a
=> [1]

看看第一个是多么误导。

已经初始化的持续警告

3 个答案: