Or can my attorney appear for me?

In California state court, in felony cases, you can have your attorney file in your presence in open court a form called a 977 waiver for certain court appearances. Usually, in misdemeanor cases, you do not have to be present if your attorney appears for you. Most important is whether the judge has ordered you present for the next court appearance. Talk to your lawyer before you ever decide not to appear for a court appearance. If you were supposed to appear and did not the judge will likely issue a warrant for your arrest!

In federal court, you usually must appear in court unless the judge specifically excuses your presence, or in certain district courts, you have a waiver of appearance on file. Again, check with your lawyer.