'width NUM NUM ...: Set the column widths for "column" mode
In "column" output mode, each column is a fixed width with values truncated to
fit.  Specify new widths using this command.  Use a negative number
to right justify and zero for default column width.'

def command_width(self, cmd):

    if (len(cmd) == 0):
        raise self.Error('You    need    to    specify    some    widths!')
    w = []
    for i in cmd:
        try:
            w.append(int(i))
        except:
            raise self.Error(("'%s'    is    not    a    valid    number" % (i,)))
    self.widths = w
