Ruby：如何检测/智能猜测CSV文件中使用的分隔符？ [英] Ruby : How can I detect/intelligently guess the delimiter used in a CSV file?

问题描述

我需要能够弄清楚在我的Ruby项目中的csv文件（逗号，空格或分号）中使用了哪个分隔符。我知道，在csv模块中有一个Sniffer类在Python中，可以用来猜测给定文件的分隔符。在Ruby中有类似的东西吗？非常感谢任何类型的帮助或想法。

I need to be able to figure out which delimiter is being used in a csv file (comma, space or semicolon) in my Ruby project. I know, there is a Sniffer class in Python in the csv module that can be used to guess a given file's delimiter. Is there anything similar to this in Ruby ? Any kind of help or idea is greatly appreciated.

推荐答案

看起来像py实现只检查几种方言：excel或excel_tab。因此，只检查，或\t的简单实现是：

Looks like the py implementation just checks a few dialects: excel or excel_tab. So, a simple implementation of something that just checks for "," or "\t" is:

COMMON_DELIMITERS = ['","',"\"\t\""]

def sniff(path)
  first_line = File.open(path).first
  return nil unless first_line
  snif = {}
  COMMON_DELIMITERS.each {|delim|snif[delim]=first_line.count(delim)}
  snif = snif.sort {|a,b| b[1]<=>a[1]}
  snif.size > 0 ? snif[0][0] : nil
end

注意：分隔符，它找到，例如，，因此要获得，，您可以更改 snif [0] [0 ] 到 snif [0] [0] [1] 。

Note: that would return the full delimiter it finds, e.g. ",", so to get , you could change the snif[0][0] to snif[0][0][1].

我使用 count（delim），因为它更快一些，但如果添加了一个由两个（或更多）字符组成的分隔符， code> - ，那么当称量类型时，它可能每次出现两次（或更多），因此在这种情况下，最好使用 scan delim）.length 。

Also, I'm using count(delim) because it is a little faster, but if you added a delimiter that is composed of two (or more) characters of the same type like --, then it would could each occurrence twice (or more) when weighing the type, so in that case, it may be better to use scan(delim).length.

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