This content originally appeared on DEV Community and was authored by Amanda Fawcett
Ruby is a general-purpose, dynamic, open source programming language that focuses on simplicity and productivity. The Ruby programming language is frequently compared to Python for their similarities. Many developers say that learning Ruby is easier if you know Python due to their similarities. However, these two languages differ in major ways.
We've created this basic introduction to help you make the transition from Python to Ruby. We'll go over their main differences and then take a dive into Ruby's syntax so you can get hands-on with Ruby code quickly.
Here's what we'll cover today:
- Ruby vs Python
- Summary of Main Code Differences
- Hello World with Ruby
- Ruby Syntax Quick Guide
- What to learn next with Ruby
Ruby vs Python
Ruby and Python are both popular programming languages known for their speed, simplicity, and user-friendly syntax. Both languages are flexible, object-oriented , dynamic, and have a lot of useful frameworks and libraries to use, particularly for web applications and web development (Ruby on Rails for Ruby or Django for Python).
Ruby is a high-level, interpreted programming language, created in 1995 by Yukihiro Matsumoto. His goal was to make an object-oriented scripting language that improved on other scripting languages of the time.
Ruby also allows for functional programming and is known for being very similar to written human languages, making it easy to learn.
Python is an interpreted, high-level general-purpose language, created by Guido van Rossum with the goal of code readability. Python is know well-loved for its robust standard library.
| Ruby | Python |
|---|---|
| No primitive data types. Everything is an object. | Has primitive types and objects |
| Mixins can be used | Mixins cannot be used |
| Less available functions. Relies mostly on methods. | Lots of available functions |
| Cannot modify built-in classes | Can modify built-in classes |
| Supports Tuples with Rinda. Other collections include Arrays, Hash, Set, and Struct. | Supports Tuples, Sets, Dictionary (Hash), and Lists |
| Iterators less common | Iterators are very common |
Career
Both languages are used by big companies. Companies that use Python include YouTube, Instagram, Spotify, Reddit, Dropbox, while Ruby is used at Hulu, Basecamp, GitHub, and Airbnb. Ruby developers also tend to make higher salaries than Python developers. StackOverflow's 2020 survey lists Ruby's global average salary at $71k and Python's at $59k.
Both Ruby and Python offer higher annual salaries than other software development languages, including PHP, JavaScript, and Java.
Machine Learning
Python is currently the go-to language for machine learning (ML) and artificial intelligence (AI) due to its extensive libraries and visualization tools. Ruby does offer some competitive options, but there is a long way to go before it will hold a torch to Python. So, if you are looking to work in data science, Python is the winner.
Web Frameworks
The main web frameworks for both Ruby and Python, Django and Ruby on Rails, are rather similar. Both are based on the classic model-view-controller (MVC) pattern, and they both provide similar repositories (PyPi for Python and RubyGems for Ruby). Both frameworks perform well and are easy to learn.
Testing Environment
Test-driven development (TDD) is pretty standard for both Ruby and Python, but Ruby does offer behavior-driven development (BDD) while Python does not, which may be useful in some cases
Community
Both languages have large, active communities, which Python's community being a bit larger, namely because Ruby is most popular for its development tool Ruby on Rails. Both communities seem to be equally active and supportive.
One benefit to Ruby is that there are unique Ruby forums and job boards since the language is more specialized in some regards.
Summary of Main Code Differences
Now that we understand the difference between Ruby and Python at a high level, let's dive into the main code differences between the two. We've compiled the main things that differ from Python below.
In the Ruby programming language:
- Strings are mutable
- You can make constants
- Parentheses for most method calls are optional
- There’s only one mutable list container (Array)
- There are no “new style” or “old style” classes
- Only
falseandnilevaluate to false, and everything else istrue - You never directly access attributes. Instead, we use method calls.
- We use
elsifinstead ofelif - We use
requireinstead ofimport - We use mixins instead of multiple inheritance
-
yieldexecutes another function that is passed as the final argument, then it resumes - We use
public,private, andprotectedfor access
Hello World with Ruby
Now that we understand how Ruby and Python differ at the code level, let's look at some actual Ruby code, starting with the classic Hello World program. Take a look below and note how simply Ruby's syntax is here.
puts "Hello World!"
Here, the puts keyword is used to print. Remember: Ruby's code is very readable, designed to emulate spoken English language.
There's even a simpler way to do this. Ruby comes with a built-in program that will show the results of any statements you feed it, called Interactive Ruby (IRB). This is the best way to learn Ruby. First, open IRB:
-
macOS: open Terminal and type
irb. Hit enter. -
Linux: open up a shel, type
irb, and hit enter. - Windows: open Interactive Ruby from the Start Menu (see the Ruby section)
If you type:
"Hello World"
You will get the following:
irb(main):001:0> "Hello World"
=> "Hello World"
The second line tells us the result of the last expression. We can print this using the puts command we learned before.
irb(main):002:0> puts "Hello World"
Hello World
=> nil
Here, => nil is the result of the expression, since puts always returns nil.
Ruby Syntax Quick Guide
Let's now quickly go over the basics of Ruby's syntax that may be different from what you're used to in Python. Note how Ruby differs and how it is similar as you read.
Variable Assignment
In Ruby, you assign a name to a variable using the assignment operator =, like so:
puts number = 1
Here is a list of the different kinds of variables in Ruby:
- Local variables (
something) - Instance variables (
@something) - Constants (
SomethingorSOMETHING) - Global variables (
$something)
Identifiers and Keywords
Keywords and identifiers are similar to Python. Identifiers are case sensitive, and they may consist of alphanumeric characters and underscore _.
Ruby's reserved keywords include the following:
Strings
In Ruby, a string is a sequence of characters inside quotation marks " ". We can also use single quotation marks.
You can concatenate strings with the plus sign +.
puts "snow" + "ball"
Output: snowball
In Ruby, multiplying a String by a number will repeat a String that many times.
puts "Ruby" * 3
Output: RubyRubyRuby
Some important methods for Ruby strings include:
sizeempty?include?gsubsplit
Pro Tip: Ruby's percentage sign
%shortcut can be used with strings and arrays
%wwill create an array of strings
%iwith create an array of symbols
%qwill create a string without quotation marks
Hashes
In Ruby, you can create a Hash by assigning a key to a value with =>. We separate these key/value pairs with commas and enclose the whole thing with curly braces.
{ "one" => "eins", "two" => "zwei", "three" => "drei" }
This defines a Hash with three key/value pairs, so we can look up three values (the strings "eins", "zwei", and "drei") using three different keys (the strings "one", "two", and "three").
Some important methods for Ruby hashes include:
key?fetchmerge-
new(for default values)
Array
In Ruby, we create an Array by separating values with commas and enclosing this list with square brackets, like so:
[1, 2, 3]
Note: Ruby Arrays always keep their order
Like in Python, there are all sorts of things you can do with Arrays. The most important methods being:
sizeempty?-
push/pop joinflatten
Here is an example of the intersection operator &, which finds the intersecting parts of our arrays:
puts ([1, 2, 3] & [2, 3, 4])
Output: 2 3
Parenthesis
In Ruby, parenthesis and semicolons are not required, but we can use them. However, we follow these basic rules:
- Do use parenthesis with method arguments:
def foo(a, b, c) - Do use parenthesis to change the priority of an operation:
(a.size + b.size) * 2 - Don't use parenthesis when defining a method that has no arguments:
def foo
Commenting
There are three main ways we can add comments to a Ruby program.
# Single line comment
# Multiple
# Lines
=begin
Block fashion
Commenting
=end
Methods
In Ruby, we define methods using the def keyword followed by method_name. IT ends with the end keyword.
def method_name
# Statement
# Statement
.
.
end
We pass parameters to our methods in parentheses.
def method_name(var1, var2, var3)
# Statement
# Statement
.
.
end
Classes
In Ruby, we create classes using the class keyword followed by the name of the class.
class Class_name
end
Note: The first letter of your class names should be a capital letter.
In Ruby, objects are created with the new method.
object_name = Class_name.new
Conditionals
Conditional statements are similar to most other languages with a few slight differences. Take a look at the examples below to get at sense of how they look in Ruby.
number = 5
if number.between?(1, 10)
puts "The number is between 1 and 10"
elsif number.between?(11, 20)
puts "The number is between 11 and 20"
else
puts "The number is bigger than 20"
end
Output: The number is between 1 and 10
Note: The
elsifandelsestatements are optional. You can have anifstatement withoutelsiforelsebranches, anifstatement only with anelse, or you could have anifstatement with one or moreelsifstatements.
Ruby also has a shorthand for working with conditional statements. So, we could write this bit of code:
number = 5
if number.odd?
puts "The number is odd."
end
As this instead:
number = 5
puts "The number is odd." if number.odd?
What to learn next with Ruby
Now that you know the basics of Ruby and know how it differs from Python, you're ready to cover more advanced topics. We recommended studying the following concepts next:
- Ruby inheritance
- Using Ruby libraries
- Nested arrays
- Ruby blocks
To get started with these concepts and get hands-on with Ruby, check out Educative's course Learn Ruby from Scratch. This introductory course offers tons of hands-on practice on all the need-to-know topics, including variables, built-in classes, objects, conditionals, blocks and much more!
By the end, you'll be a confident Ruby developer, ready to take on complex projects!
Happy learning!
Continue reading about Ruby
- 8 tricks and best practices for improving your Ruby code
- Getting Started with Ruby on Rails: build a web app with Ruby
- Docker with Rails: Benefits and Top Use Cases
This content originally appeared on DEV Community and was authored by Amanda Fawcett
Amanda Fawcett | Sciencx (2021-04-20T16:52:40+00:00) Ruby Tutorial for Python Programmers: how to make the switch. Retrieved from https://www.scien.cx/2021/04/20/ruby-tutorial-for-python-programmers-how-to-make-the-switch/
Please log in to upload a file.
There are no updates yet.
Click the Upload button above to add an update.