I have a bmw and the key doesn't come out of the ignition

a lot of new bmw needs programming when install a new battery.

new battery need to programmed with the car's ecu

Sounds like a flat battery ... Charge it or replace it

u need a new key or its the ignition its self if u go to the dealer ship u can buy a new ignition and the key comes with it or u can try a new key but if u buy a key its just as expensive as duying the whole ignition

its ounds like the starting motor but get the anty theft checked as the cut off might be playing up

If it`s not broke off in ignition try wiggling stearing wheel while trying to remove key if it still doesn`t want to come out try vise grips but be carefull not to brake key because if you do break key off in it then you will have to remove steering wheel to get to where pin is holding ignition switch and you will have to replace ignition switch.

Check the battery cables a loose connection can cause this. It they are tight check ignition switch.
With 2 key failures in such a short time it may be security ignition interrupt issue

Sounds like a faulty ignition barrel! If you take off the trims underneath the steering column you'll be able to gain access to the ignition barrel casing where the key goes. By undoing the casing you'll be able to turn off the engine with a simple flat bladed screwdriver.

Ignition barrels arent too expensive to have replaced, the other problem that might occur is the chance of needing a new set of keys or to have your current keys programmed to the new barrel (Normally a new set of keys is the common procedure with a new barrel)!

Hope this helps

no you can not

If it doesnot crank at all look for starter/starter relay/starter relay fuse. Most probably wiring coming to starter is loose, try to tighten it more (push towards starter). Also I would check antiteft system (if it is provided for your car) as some BMW have immobilizers.
If it cranks no start look for spark plugs, wires, distributor cap, coolant temperature sensor, O2 sensor, fueling system (fuel pump cutoof switch, fule pump relay, fuel filter).
Please kindly let me know if you need more information, or kindly provide me with more details to assist you better
Good Luck

Hello!

Sounds like a stuck ignition relay. 
Try tapping with something ******* the ignition switch when this happens, see if it helps.
If it does consider replacing the ignition switch.

Hope this helps!