Ruby Kernel Example¶

This notebook demonstrates using the Ruby kernel (IRuby) for scripting and web development tasks.

Kernel Information¶

This notebook uses the Ruby kernel (IRuby). To use this kernel, you need to install:

gem install iruby
iruby register --force

In [ ]:

# Display Ruby version and information
puts "Ruby version: #{RUBY_VERSION}"
puts "Ruby platform: #{RUBY_PLATFORM}"
puts "Ruby engine: #{RUBY_ENGINE}"

# Display Ruby version and information puts "Ruby version: #{RUBY_VERSION}" puts "Ruby platform: #{RUBY_PLATFORM}" puts "Ruby engine: #{RUBY_ENGINE}"

Ruby Features¶

Ruby is excellent for:

• Web Development (Ruby on Rails)
• Scripting and Automation
• DevOps and Configuration Management
• Rapid Prototyping

In [ ]:

# Example: Working with classes and objects
class ProgrammingLanguage
  attr_accessor :name, :type, :year_created
  
  def initialize(name, type, year)
    @name = name
    @type = type
    @year_created = year
  end
  
  def age
    Time.now.year - @year_created
  end
  
  def to_s
    "#{@name} (#{@type}) - Created in #{@year_created}, #{age} years old"
  end
end

# Create language objects
languages = [
  ProgrammingLanguage.new("Ruby", "Dynamic", 1995),
  ProgrammingLanguage.new("Python", "Dynamic", 1991),
  ProgrammingLanguage.new("Julia", "Dynamic", 2012),
  ProgrammingLanguage.new("R", "Statistical", 1993)
]

puts "Programming Languages:"
languages.each { |lang| puts lang }

# Example: Working with classes and objects class ProgrammingLanguage attr_accessor :name, :type, :year_created def initialize(name, type, year) @name = name @type = type @year_created = year end def age Time.now.year - @year_created end def to_s "#{@name} (#{@type}) - Created in #{@year_created}, #{age} years old" end end # Create language objects languages = [ ProgrammingLanguage.new("Ruby", "Dynamic", 1995), ProgrammingLanguage.new("Python", "Dynamic", 1991), ProgrammingLanguage.new("Julia", "Dynamic", 2012), ProgrammingLanguage.new("R", "Statistical", 1993) ] puts "Programming Languages:" languages.each { |lang| puts lang }

In [ ]:

# Example: Ruby's elegant syntax
# Array operations
numbers = [1, 2, 3, 4, 5]

puts "Original array: #{numbers}"
puts "Doubled: #{numbers.map { |n| n * 2 }}"
puts "Even numbers: #{numbers.select(&:even?)}"
puts "Sum: #{numbers.reduce(:+)}"

# String manipulation
text = "ruby is awesome"
puts "\nString operations:"
puts "Capitalized: #{text.capitalize}"
puts "Reversed: #{text.reverse}"
puts "Word count: #{text.split.length}"

# Example: Ruby's elegant syntax # Array operations numbers = [1, 2, 3, 4, 5] puts "Original array: #{numbers}" puts "Doubled: #{numbers.map { |n| n * 2 }}" puts "Even numbers: #{numbers.select(&:even?)}" puts "Sum: #{numbers.reduce(:+)}" # String manipulation text = "ruby is awesome" puts "\nString operations:" puts "Capitalized: #{text.capitalize}" puts "Reversed: #{text.reverse}" puts "Word count: #{text.split.length}"

Ruby Blocks and Iterators¶

In [ ]:

# Example: Blocks and yield
def measure_time
  start_time = Time.now
  yield if block_given?
  end_time = Time.now
  puts "Execution time: #{(end_time - start_time) * 1000} ms"
end

# Using the block
measure_time do
  # Simulate some work
  sum = 0
  10000.times { |i| sum += i }
  puts "Sum calculated: #{sum}"
end

# Custom iterator
class Fibonacci
  def self.up_to(max)
    a, b = 0, 1
    while a <= max
      yield a
      a, b = b, a + b
    end
  end
end

puts "\nFibonacci numbers up to 100:"
Fibonacci.up_to(100) { |f| print "#{f} " }
puts

# Example: Blocks and yield def measure_time start_time = Time.now yield if block_given? end_time = Time.now puts "Execution time: #{(end_time - start_time) * 1000} ms" end # Using the block measure_time do # Simulate some work sum = 0 10000.times { |i| sum += i } puts "Sum calculated: #{sum}" end # Custom iterator class Fibonacci def self.up_to(max) a, b = 0, 1 while a <= max yield a a, b = b, a + b end end end puts "\nFibonacci numbers up to 100:" Fibonacci.up_to(100) { |f| print "#{f} " } puts

In [ ]:

# Example: Metaprogramming
class DynamicClass
  # Define methods dynamically
  [:hello, :goodbye, :welcome].each do |method_name|
    define_method(method_name) do |name|
      "#{method_name.to_s.capitalize}, #{name}!"
    end
  end
end

obj = DynamicClass.new
puts obj.hello("World")
puts obj.goodbye("Friend")
puts obj.welcome("Ruby Developer")

# Example: Metaprogramming class DynamicClass # Define methods dynamically [:hello, :goodbye, :welcome].each do |method_name| define_method(method_name) do |name| "#{method_name.to_s.capitalize}, #{name}!" end end end obj = DynamicClass.new puts obj.hello("World") puts obj.goodbye("Friend") puts obj.welcome("Ruby Developer")

Data Visualization in Ruby¶

While Ruby doesn't have as many data visualization libraries as Python, you can still create visualizations:

In [ ]:

# Example: Simple ASCII chart
def ascii_bar_chart(data)
  max_value = data.values.max
  max_label_length = data.keys.map(&:length).max
  
  data.each do |label, value|
    bar_length = (value.to_f / max_value * 30).round
    bar = "#" * bar_length
    printf "%-#{max_label_length}s | %s %d\n", label, bar, value
  end
end

language_popularity = {
  "Python" => 100,
  "Ruby" => 60,
  "Julia" => 30,
  "R" => 50
}

puts "Language Popularity (Jupyter Kernel Usage):"
ascii_bar_chart(language_popularity)

# Example: Simple ASCII chart def ascii_bar_chart(data) max_value = data.values.max max_label_length = data.keys.map(&:length).max data.each do |label, value| bar_length = (value.to_f / max_value * 30).round bar = "#" * bar_length printf "%-#{max_label_length}s | %s %d\n", label, bar, value end end language_popularity = { "Python" => 100, "Ruby" => 60, "Julia" => 30, "R" => 50 } puts "Language Popularity (Jupyter Kernel Usage):" ascii_bar_chart(language_popularity)

Installing Ruby Gems¶

You can install Ruby gems directly from a notebook cell:

In [ ]:

# Example of installing gems (commented out to avoid actual installation)
# system('gem install json')
# system('gem install httparty')
# system('gem install nokogiri')

puts "Use system('gem install <gem_name>') to install Ruby gems"

# Example of installing gems (commented out to avoid actual installation) # system('gem install json') # system('gem install httparty') # system('gem install nokogiri') puts "Use system('gem install ') to install Ruby gems"

Summary¶

The Ruby kernel (IRuby) provides:

• Full access to Ruby's elegant syntax
• Object-oriented programming features
• Metaprogramming capabilities
• Access to Ruby gems ecosystem
• Great for web development and scripting

While less common than Python for data science, Ruby in Jupyter is excellent for:

• Teaching Ruby programming
• Rapid prototyping
• DevOps scripting
• Web API exploration