k2works

require 'csv'

headers = %w(name age gender)
people = [
   ['alice',14,'female'],
   ['bob',32,'unknown'],
   ['carol',17,'female']   
]

csv_string = CSV.generate('', write_headers: true, headers: headers) { |csv|

k2works

# coding: utf-8
CSV.open('people.csv').each do |row|
   # 何かしらの処理
end

CSV.open('people.csv', 'a') do |csv|
   csv.flock(File::LOCK_EX)

   people.each do |person|
	  csv << person

k2works

# coding: utf-8
require 'set'

a = %w(a b c d).to_set
b = %w(c d e f).to_set

# どちらかに含まれる要素の集合（和集合）
p a | b # >> #<Set: {"a", "b", "c", "d", "e", "f"}>
p a.union(b) # >> #<Set: {"a", "b", "c", "d", "e", "f"}>

k2works

require 'set'

a = %w(Alice Bob Charlie).to_set
b = %w(Alice Bob).to_set

p a.superset?(b) # >> true
p b.subset?(a) # >> true
p a.proper_superset?(b) # >> true
p b.proper_subset?(a) # >> true

k2works

# coding: utf-8
require 'time'

# Time#parseはTimeオブジェクトを返す
Time.parse('2011-04-01 16:01').class # => Time

# 様々な形式の時刻を表す文字列をTimeオブジェクトに変換する
Time.parse('2011-04-01 16:01')	# => 2011-04-01 16:01:00 +0900
Time.parse('2011/04/01 16:01')	# => 2011-04-01 16:01:00 +0900
Time.parse('2012-01-29 14:13:08 +900')	# => 2011-04-01 16:01:00 +0900

k2works

# coding: utf-8
require 'date'

# 年月日から日付オブジェクトを得る
date = Date.new(2011,4,1)		# => #<Date: 2011-04-01 ((2455653j,0s,0n),+0s,2299161j)>

# 日付を指定した書式の文字列で表現する
date.strftime('%Y/%m/%d')		# => "2011/04/01"
date.strftime('%Y/%m/%d %H:%M:%S') # => "2011/04/01 00:00:00"

k2works

# coding: utf-8
require 'date'

# 年月日からDateTimeオブジェクトを得る
date = DateTime.new(2011,4,1,4,4,23)
# => #<DateTime: 2011-04-01T04:04:23+00:00 ((2455653j,14663s,0n),+0s,2299161j)>

# 日時を指定した書式の文字列で表現する
date.strftime('%Y%m%d %H:%M:%S') # => "20110401 04:04:23"

k2works

require 'rack'

class RackApplication
   def call(env)
	  [200, {'Content-Type' => 'text/plain'},['Hello!']]
   end
end

run RackApplication.new

k2works

require 'rack'

class RackApplication
   def call(env)
	  request = Rack::Request.new(env)
	  response = if request.path_info == '/'
					body = "#{request.request_method}: Hello! #{request.params['name']}!"
					Rack::Response.new(body, 200, {'Content-Type' => 'text/plain'})
				 else
					Rack::Response.new('Not Found',404,{'Content-Type' => 'text/plain'})

k2works

require 'rack'

class RackApplication
   def call(env)
	  [200, {'Content-Type' => 'text/plain'},['Hello!']]
   end
end

use Rack::ShowStatus
use Rack::Auth::Basic do |username,password|