Catch any error in Python

Using except by itself will catch any exception short of a segfault.

try:
    something()
except:
    fallback()

You might want to handle KeyboardInterrupt separately in case you need to use it to exit your script:

try:
    something()
except KeyboardInterrupt:
    return
except:
    fallback()

There's a nice list of basic exceptions you can catch here. I also quite like the traceback module for retrieving a call stack from the exception. Try traceback.format_exc() or traceback.print_exc() in an exception handler.

try:
    # do something
except Exception, e:
    # handle it

For Python 3.x:

try:
    # do something
except Exception as e:
    # handle it