Python - User Defined with Statement

Original Sources:

---

Used in this file:

---

~ Ex.:

define a class with dunder methods __enter__ and __exit__, the first will be called at the start of the with statement, and the last at the end.

class A:
    def __enter__(self, code):
       print code
 
    def __exit__(..):
       pass

and then:

with A():
   f()
   g()

---