Indeed.
The entire article largely read like "Python developer learns Ruby", and on top of that now fairly dated Ruby, though I'll make some concessions for him wanting to show a close parallel to the Python. I wish he'd signposted more clearly that these are examples, though, because as it stands it implies this is how to do things, while it really is not.
E.g. his "Stuff" example can be reduced to:
class Stuff
def initialize
@a_list = [1, 2, 3, 4]
end
# The ellipses here are part of the Ruby code for 'forward
# all the arguments, including the a block if passed'
def each(...) = @a_list.each(...)
include Enumerable
end
Stuff.new.each {|item| puts item }
puts Stuff.new.map {|item| item}
puts Stuff.new.select{|item| item.even?}
One could argue about my use of "..." and endless def, but one certainly would not typically implement each when forwarding to an Array by using a for loop to iterate over it other than to make it relatable to Python developers...
And, more controversially perhaps, the last three lines can be reduced to:
Stuff.new.each { puts _1 }
puts Stuff.new.map.to_a
puts Stuff.new.select(&:even?)
The first one is one that will cause arguments. The second just showcases that map is pointless here other than as an example - map here effectively just a slow way of duplicating the array, but notably first when forcible evaluated as map without a block will return an Enumerator, and "&:even?" is fairly idiomatic for "call to_proc on this symbol and apply it to the argument", but some might still not be familiar with it.