Question

Stock data.csv

1425904377,22532.1309,22533.6992,22524.0703,22524.0703,0
1425904438,22533.4395,22533.4395,22529.2793,22532.2207,0
1425904499,22531.8809,22536.0801,22531.8809,22533.2793,0
1425904559,22532.4297,22534.7207,22530.7598,22532.0996,0
1425904618,22535.7695,22535.9297,22530.6094,22532.2500,0
1425904679,22536.0703,22539.2598,22535.5605,22535.6094,0
1425904738,22542.8809,22544.2305,22536.3594,22536.3594,0
1425904797,22540.6504,22544.0391,22538.5000,22542.9707,0
1425904857,22545.2891,22552.5098,22538.5898,22538.9004,0
1425904860,22547.0703,22547.0703,22547.0703,22547.0703,0

我必须做两件事：

按timestamp排序行（第一个值）
删除重复项（密钥：timestamp）

我尝试了这个，但它没有工作：

my_csv = CSV.read("public/#{symbol}.csv")
my_csv.sort_by!(&:first)


open("public/#{symbol}.csv", 'w') { |f|
  my_csv.each do |row|
    f.puts "#{row.join(",")}"
  end
}

Answer 1

require 'csv'
my_csv = CSV.read 'data.csv'

my_csv.sort! { |a, b| a[0].to_i <=> b[0].to_i }
my_csv.uniq!(&:first)

my_csv.each { |line| p line }

输出：

["1425904377", "22532.1309", "22533.6992", "22524.0703", "22524.0703", "0"]
["1425904438", "22533.4395", "22533.4395", "22529.2793", "22532.2207", "0"]
["1425904499", "22531.8809", "22536.0801", "22531.8809", "22533.2793", "0"]
["1425904559", "22532.4297", "22534.7207", "22530.7598", "22532.0996", "0"]
["1425904618", "22535.7695", "22535.9297", "22530.6094", "22532.2500", "0"]
["1425904679", "22536.0703", "22539.2598", "22535.5605", "22535.6094", "0"]
["1425904738", "22542.8809", "22544.2305", "22536.3594", "22536.3594", "0"]
["1425904797", "22540.6504", "22544.0391", "22538.5000", "22542.9707", "0"]
["1425904857", "22545.2891", "22552.5098", "22538.5898", "22538.9004", "0"]
["1425904860", "22547.0703", "22547.0703", "22547.0703", "22547.0703", "0"]

CSV.read会将文件读取为数组
我们可以使用sort进行回调，在回调中我们得到2项要比较
我们比较第一项（时间戳），我们将其转换为整数，以确保我们得到整数比较。
我们使用"spaceship operator"进行比较;它将返回0,1或-1（参见链接），这是sort期望块返回的内容。
我们使用uniq!就地修改数组，在第一个条目中使用它。

按第一个值对CSV文件的行进行排序

1 个答案: