class Foo(object):

  def __init__(self):
    self.myattr = 0

  def bar(self):
    self.myattr += 1
    return self

var Car = function () {
    return {
        gas : 0,
        miles : 0,
        drive : function (d) {
            this.miles += d;
            this.gas -= d;
            return this;
        },
        fill : function (g) {
            this.gas += g;
            return this;
        },
    };
}

var c = Car();
c.fill(100).drive(50);
c.miles => 50;
c.gas => 50;

a.doA()
a.doB()
a.doC()

a.doA().doB().doC()

function doA():
    return new A(value + 1)

function doB():
    return new A(value * 2)

function doC():
    return new A(sqrt(value))

foo.modify1().modify2()

# without `return self`
foo.modify1()
foo.modify2()

foo = foo.modify()

# without `return self`
foo.modify()