In France you need to earn 3 times the price of the lawn, and you need warrants (garants) : people who will be forced to pay if you ever don't. To prove you can pay, you need 3 months of salary sheets. You need to prove your job is not a CDD (short determined time). You need to show insurances and prove your identity too of course. Half of those are not legal, but landlords don't care because you're in competition : you visit the apartment with a dozen of other people who want a place to sleep too. And the landlord will choose the chosen one as he pleases.

It depends on the place, but Lyon is absolute madness to find an apartment.