handle zero values that cause division error

        # do not report any changes then

        prev = curr

    change_ratios = [abs(float(curr[i]) / float(prev[i]) - 1) > THRESH for i in cols]

    changes_found = any(change_ratios)

    changes_found = False

    for c in cols:

        if curr[c] == prev[c]:

            abs_perc_change = 0

        else:

            try:

                abs_perc_change = abs(float(curr[c]) / float(prev[c]) - 1)

            except ZeroDivisionError:

                # in some cases, such as missing instrumentation, values can be zero, so catch that here

                # from the first if we know that curr can not be 0 too -> report change

                abs_perc_change = THRESH + 1

        if abs_perc_change > THRESH:

            changes_found = True

            break

    if changes_found:

        print("Previous log line:", prev)