<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def except_handle(tokens):
 """Process except statements."""

    if len(tokens) == 1:
        errs, asname = tokens[0], None
    elif len(tokens) == 2:
        errs, asname = tokens
    else:
        raise CoconutInternalException("invalid except tokens", tokens)
    out = "except "
    if "list" in tokens:
        out += "(" + errs + ")"
    else:
        out += errs
    if asname is not None:
        out += " as " + asname
    return out