First things first :) reading books is an excellent approach to problem solving; it's the difference between band-aid fixes and long-term investments in solving problems. Never miss an opportunity to learn. :D
You might choose to interpret the 1 as a number, but environment variables don't care. They just pass around strings:
The argument envp is an array of character pointers to null-
terminated strings. These strings shall constitute the
environment for the new process image. The envp array is
terminated by a null pointer.
(From environ(3posix).)
You access environment variables in python using the os.environ dictionary-like object:
>>> import os
>>> os.environ["HOME"]
'/home/sarnold'
>>> os.environ["PATH"]
'/home/sarnold/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games'
>>> os.environ["PATH"] = os.environ["PATH"] + ":/silly/"
>>> os.environ["PATH"]
'/home/sarnold/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/silly/'