• Ruby 之 csv 文件读写


    csv 文件写入

    1. require 'csv'
    2. title = ["col1", "col2"]
    3. contents = [["row11", "row12"], ["row21", "row22"]]
    4. csv1 = CSV.open("test1.csv", "wb") do |csv|
    5. # write file title
    6. csv << title
    7. # write file body
    8. contents.each do |line|
    9. csv << line
    10. end
    11. end
    12. puts csv1.class
    13. puts csv1.inspect
    14. # UTF-8编码的文件,开头会加入BOM来表明编码方式
    15. csv2 = CSV.generate("\xEF\xBB\xBF") do |csv|
    16. # write file title
    17. csv << title
    18. # write file body
    19. contents.each do |line|
    20. csv << line
    21. end
    22. end
    23. File.open("test2.csv", "wb"){|f| f << csv2}
    24. puts csv2.class
    25. puts csv2.inspect
    1. Array
    2. [["row11", "row12"], ["row21", "row22"]]
    3. String
    4. "col1,col2\nrow11,row12\nrow21,row22\n"

    csv 文件读取

    test.csv

    1. col1,col2
    2. row11,row12
    3. row21,row22

    按行读取 

    1. require 'csv'
    2. csv3 = []
    3. CSV.open("test1.csv") do |csv|
    4. csv.each do |line|
    5. csv3 << line
    6. end
    7. end
    8. puts csv3.class
    9. puts csv3.inspect
    10. csv4 = []
    11. File.open("test2.csv", "rb") do |f|
    12. f.each do |line|
    13. csv4 << line
    14. end
    15. end
    16. puts csv4.class
    17. puts csv4.inspect
    1. Array
    2. [["col1", "col2"], ["row11", "row12"], ["row21", "row22"]]
    3. Array
    4. ["\xEF\xBB\xBFcol1,col2\n", "row11,row12\n", "row21,row22\n"]

    以键值对形式读取

    1. require 'csv'
    2. rows = CSV.read("test.csv", headers:true)
    3. title = rows.headers
    4. contents = []
    5. rows.each do |row|
    6. contents << row.to_h
    7. end
    8. puts title.inspect
    9. puts contents.inspect
    10. puts
    11. rows = CSV.parse("col1,col2\nrow11,row12\nrow21,row22", headers:true)
    12. title = rows.headers
    13. contents = []
    14. rows.each do |row|
    15. contents << row.to_h
    16. end
    17. puts title.inspect
    18. puts contents.inspect
    1. ["col1", "col2"]
    2. [{"col1"=>"row11", "col2"=>"row12"}, {"col1"=>"row21", "col2"=>"row22"}]
    3. ["col1", "col2"]
    4. [{"col1"=>"row11", "col2"=>"row12"}, {"col1"=>"row21", "col2"=>"row22"}]
  • 相关阅读:
    MyBatis ognl.NoSuchPropertyException 或者 Invalid bound statement (not found)
    CF797E Array Queries
    C# list泛型集合(线性表)
    2.4.1 用户态协议栈设计实现
    Hive的静态分区与动态分区
    (Vue2版本)Uniapp编写H5项目
    模板匹配与像素统计
    Nginx配置整合:基本概念、命令、反向代理、负载均衡、动静分离、高可用
    FPGA解析B码----连载3
    优维EasyOps,打造新一代运维新方式
  • 原文地址:https://blog.csdn.net/TomorrowAndTuture/article/details/133888876