The Paris train and bus transport system, RATP, has stopped selling the Carte Orange week pass / month pass and started selling the Passe Navigo Découverte, which is aimed at visitors and tourists to Paris.
For €5, the Passe Navigo Découverte card can be purchased on the spot at any metro ticket window in Paris, which can then be loaded with 2 to 6 zones of travel, for a week or a month. A 2 Zone Passe Navigo Découverte will cover Paris up to the financial center of La Défense on the western edge of Paris, home of the Grande Arche & Société Générale, to Chateau de Vincennes on the eastern edge of the city, home of the 12th century medieval keep.
A 6 Zone Passe Navigo Découverte is good for trains from Paris out to Chateau Fontainebleau, Chateau Versailles, Euro Disney, Airport Paris-Charles de Gaulle (CDG) Terminals 1 and 2 and Airport Paris-Orly (ORY).
Find out more about the Passe Navigo Découverte at Paris by Train.
Paris by Train 
Be careful. Unfortunately if you broke your “Passe Navigo Découverte” card you can’t have another one without paying the 5 euros and pay again for the 2 or 6 zones of travel. (about 70 euros for 3 zones)
The Carte Orange was more easy to use in this case because it was possible to only change the broken ticket for free.
Anyway enjoy your stay in France.