test.rb

# Ruby, no bueno
a = 1
def f()
  a=2
end
puts a # => 1

# Ruby, works
a = 1
__sym123 = binding
f = lambda do
  __sym123.eval("a=2")
end
f.call
puts a # => 2

# Python, hacky
a = 1
def f():
    global a
    a = 2
print(a) # => 2
  
# Also Python, also hacky af
def f():
	a = 1
	def g():
		nonlocal a
		a = 2
	g()
	print(a) # => 2
  
; Lisp, works
(def a 1)
(def (f)
  (set! a 2))
(f)
(puts a) ; => 2