def grep_log_for_errors(self, filename='system.log'):
        return self.grep_log_for_errors_from(seek_start=getattr(self, 'error_mark', 0))
return n random rows of data (and also the other len(data)-n rows)
dataset/ETHPy150Open pcmanus/ccm/ccmlib/node.py/Node.grep_log_for_errors--crossover with--dataset/ETHPy150Open jesolem/PCV/PCV/tools/ransac.py/random_partition