According to the California Department of Motor Vehicles, if you are a visitor in California over 18 and have a valid driver license from your home state or country, you may drive in this state without getting a California driver license as long as your home state or country license remains valid.

If you take a job here or become a resident, you must get a California driver license within 10 days. Residency is established by voting in a California election, paying resident tuition, filing for a homeowner's property tax exemption, or any other privilege or benefit not ordinarily extended to nonresidents. If you have a license from another country, you will be required to take a driving test

While the State of California does not recognize an International Driving Permit (IDP) as a valid driver license, California does recognize a valid driver license that is issued by a foreign jurisdiction (country, state, territory) of which the license holder is a resident.

The IDP is only a translation of information contained on a person's foreign driver license and is not required to operate a motor vehicle in California. Citations issued to a person in California who has an IDP, but does not have a California driver license will be placed on the Department of Motor Vehicle database.

The actual California Vehicle Code regarding non-resident drivers is number 12502 and states that a nonresident over the age of 18 years having in his or her immediate possession a valid driver's license issued by a foreign jurisdiction of which he or she is a resident may operate a motor vehicle in this state without obtaining a driver's license.

If your European license is not the same as a valid foreign license from your home country, you should check with the CA DMV to make certain this will still allow you to drive around legally in Los Angeles and other parts of California. If you find out you need a CA license, you can find out information on how to do so from the DMV as well.