After reading PEP 342 [2010-01] i goofed around with simple generators, I guess

generators.py

#!/usr/bin/env python
import sys

def mahgen():
	v = "START"
	c = 0
	while 1:
		v = yield (v, c)
		c += 1

def main():
	gen = mahgen()
	print gen.send(None) # == gen.next()
	print gen.send("PIE")
	print gen.send("HAM")
	print gen.send("MORE PIE")
	print gen.send("CAKE")

if __name__ == "__main__": sys.exit(main())

output.txt

('START', 0)
('PIE', 1)
('HAM', 2)
('MORE PIE', 3)
('CAKE', 4)