如何检查下一个iter项而不进行Python中的For循环

时间:2016-03-10 20:37:25

标签: python python-2.7 for-loop iterator next

当通过next(iter)进行迭代时,我想基本上将网络组合在一起,我通过计算每行中出现的项目数来做到这一点,如果它有7个项目,则它是条目的开头。

然后我在输入行下面查找行,直到找到包含7个项目的另一行。然后重新开始这个过程。

唯一的问题是当我通过line = next(bgp_table_iter)访问“下一行”并打破循环时,如果“下一行”有7个项目意味着开始一个新条目,当它从{{1开始它再次迭代到下一行,跳过应该有7个项目的原始“下一行”,并且是新条目的开头。

哪一端会跳过其他所有条目。

我怎么能阻止跳过?或者让For循环触发器在中断时转到上一次迭代?

for line in bgp_table_iter:

输出:

def show_ip_bgp():
    data = test_output_short.split('RPKI validation codes: V valid, I invalid, N Not found\n\n     Network          Next Hop            Metric LocPrf Weight Path\n')
    bgp_table = data[1]
    bgp_table = re.sub("     Network          Next Hop            Metric LocPrf Weight Path\n","",bgp_table)
    bgp_table = re.sub("\*","",bgp_table)

    bgp_table_list = bgp_table.split('\n')

    bgp_table_iter = iter(bgp_table_list)

    overall_dict = {}
    index = 0
    for line in bgp_table_iter:
        # print line.split(), len(line.split())

        current_line = line.split()
        # If 7 items are in the list it's the start of a network
        if len(current_line) == 7:
            best = True if '>' in current_line[0] else False
            network = current_line[1]
            attached_ip = current_line[2]
            print "Found Starting Network", network, attached_ip, "Best Path: {}".format(best)
            for i in range(0,1000):
                line = next(bgp_table_iter)
                subline_line = line.split()
                best_sub = 'True' if '>' in subline_line[0] else 'False'
                if len(subline_line) == 6:
                    print 'Sub:', subline_line[1], "Best Path: {}".format(best_sub)
                elif len(subline_line) == 5:
                    print 'Sub:', subline_line[1], "Best Path: {}".format(best_sub)
                elif len(subline_line) == 7:
                    break



test_output_short = '''BGP table version is 3538854, local router ID is 10.15.1.81
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
 * i 10.0.1.0/24      10.8.111.45              0    115      0 i
 *>i                  10.8.11.45               0    120      0 i
 * i                  10.8.11.45               0    120      0 i
 * i                  10.8.11.45               0    120      0 i
 * i 10.0.3.0/29      10.8.111.45              0    115      0 i
 *>i                  10.8.11.45               0    120      0 i
 * i                  10.8.11.45               0    120      0 i
 * i                  10.8.11.45               0    120      0 i
 * i 10.8.0.0/16      10.9.0.1                 0     50      0 i
 * i                  10.8.0.1                 0     50      0 i
 *>                   0.0.0.0                  0         32768 i
 * i 10.9.0.0/16      10.9.0.1                 0     50      0 i
 * i                  10.8.0.1                 0     50      0 i
 *>                   0.0.0.0                  0         32768 i
 *>i 10.10.2.0/24     10.8.10.2                0    100      0 i
 * i                  10.8.10.2                0    100      0 i
 * i                  10.8.10.2                0    100      0 i
 * i 10.10.5.0/24     10.8.142.15              0     85      0 i
 *>i                  10.8.42.15               0    100      0 i
 * i                  10.8.42.15               0    100      0 i
 * i                  10.8.42.15               0    100      0 i
 *>i 10.10.7.0/24     10.8.40.84               0    100      0 i
 * i                  10.8.40.84               0    100      0 i
 * i                  10.8.40.84               0    100      0 i
 *>i 10.10.8.0/24     10.8.10.8                0    100      0 i
 * i                  10.8.110.8               0     85      0 i
 * i                  10.8.10.8                0    100      0 i
 * i                  10.8.10.8                0    100      0 i
 *>i 10.10.11.0/24    10.8.42.8                0    100      0 i
 * i                  10.8.42.8                0    100      0 i
 * i                  10.8.42.8                0    100      0 i
 * i                  10.9.42.8                0    100      0 i
 * i 10.10.12.0/24    10.8.10.12               0    100      0 i
 * i                  10.8.10.12               0    100      0 i
 *>i                  10.8.10.12               0    100      0 i'''

更新

建议的修复程序似乎有效,直到我运行测试。它确实使所有网络看起来都像。

def show_ip_bgp():     data = test_output_very_short.split('RPKI验证码:V有效,我无效,N未找到\ n \ n网络下一跳度量标准LocPrf权重路径\ n')     bgp_table =数据[1]     bgp_table = re.sub(“网络下一跳度量标准LocPrf权重路径\ n”,“”,bgp_table)     bgp_table = re.sub(“*”,“”,bgp_table)

>>> show_ip_bgp()
Found Starting Network 10.0.1.0/24 10.8.111.45 Best Path: False
Sub: 10.8.11.45 Best Path: True
Sub: 10.8.11.45 Best Path: False
Sub: 10.8.11.45 Best Path: False
Found Starting Network 10.8.0.0/16 10.9.0.1 Best Path: False
Sub: 10.8.0.1 Best Path: False
Sub: 0.0.0.0 Best Path: True
Found Starting Network 10.10.2.0/24 10.8.10.2 Best Path: True
Sub: 10.8.10.2 Best Path: False
Sub: 10.8.10.2 Best Path: False
Found Starting Network 10.10.7.0/24 10.8.40.84 Best Path: True
Sub: 10.8.40.84 Best Path: False
Sub: 10.8.40.84 Best Path: False
Found Starting Network 10.10.11.0/24 10.8.42.8 Best Path: True
Sub: 10.8.42.8 Best Path: False
Sub: 10.8.42.8 Best Path: False
Sub: 10.9.42.8 Best Path: False

输出:

bgp_table_list = bgp_table.split('\n')

bgp_table_iter = iter(bgp_table_list)

overall_dict = {}
index = 0
for i, line in enumerate(bgp_table_list):
    # print line.split(), len(line.split())

    current_line = line.split()
    # If 7 items are in the list it's the start of a network
    if len(current_line) == 7:
        best = True if '>' in current_line[0] else False
        network = current_line[1]
        attached_ip = current_line[2]
        print "Found Starting Network", network, attached_ip, "Best Path: {}".format(best)
        for i in range(0,1000):
            line = bgp_table_list[i+1]
            print i
            subline_line = line.split()
            best_sub = 'True' if '>' in subline_line[0] else 'False'
            if len(subline_line) == 6:
                print 'Sub:', subline_line[1], "Best Path: {}".format(best_sub)
            elif len(subline_line) == 5:
                print 'Sub:', subline_line[1], "Best Path: {}".format(best_sub)
            elif len(subline_line) == 7:
                line = bgp_table_list[i+1]
                break

每次显示时索引号都会回到0,打印出要检查的行的索引。

1 个答案:

答案 0 :(得分:3)

不要强迫它为iter,而是继续将其用作list,然后使用enumeratelist中了解您的位置。

编辑:Chaning首先枚举以使用index,第二个循环的范围以1而不是0开头,并使用except子句检查line = bgp_table_list[index+i]行当它到达文件末尾时。

for index, line in enumerate(bgp_table_list):
    # print line.split(), len(line.split())

    current_line = line.split()
    # If 7 items are in the list it's the start of a network
    if len(current_line) == 7:
        best = True if '>' in current_line[0] else False
        network = current_line[1]
        attached_ip = current_line[2]
        print "Found Starting Network", network, attached_ip, "Best Path: {}".format(best)
        for i in range(1, 1000):
            try:
                line = bgp_table_list[index+i]
            except IndexError:
                break
            subline_line = line.split()
            best_sub = 'True' if '>' in subline_line[0] else 'False'
            if len(subline_line) == 6:
                print 'Sub:', subline_line[1], "Best Path: {}".format(best_sub)
            elif len(subline_line) == 5:
                print 'Sub:', subline_line[1], "Best Path: {}".format(best_sub)
            elif len(subline_line) == 7:
                break

我的输出(不确定是否正确,提供以便您可以判断)

Found Starting Network 10.0.1.0/24 10.8.111.45 Best Path: False
Sub: 10.8.11.45 Best Path: True
Sub: 10.8.11.45 Best Path: False
Sub: 10.8.11.45 Best Path: False
Found Starting Network 10.0.3.0/29 10.8.111.45 Best Path: False
Sub: 10.8.11.45 Best Path: True
Sub: 10.8.11.45 Best Path: False
Sub: 10.8.11.45 Best Path: False
Found Starting Network 10.8.0.0/16 10.9.0.1 Best Path: False
Sub: 10.8.0.1 Best Path: False
Sub: 0.0.0.0 Best Path: True
Found Starting Network 10.9.0.0/16 10.9.0.1 Best Path: False
Sub: 10.8.0.1 Best Path: False
Sub: 0.0.0.0 Best Path: True
Found Starting Network 10.10.2.0/24 10.8.10.2 Best Path: True
Sub: 10.8.10.2 Best Path: False
Sub: 10.8.10.2 Best Path: False
Found Starting Network 10.10.5.0/24 10.8.142.15 Best Path: False
Sub: 10.8.42.15 Best Path: True
Sub: 10.8.42.15 Best Path: False
Sub: 10.8.42.15 Best Path: False
Found Starting Network 10.10.7.0/24 10.8.40.84 Best Path: True
Sub: 10.8.40.84 Best Path: False
Sub: 10.8.40.84 Best Path: False
Found Starting Network 10.10.8.0/24 10.8.10.8 Best Path: True
Sub: 10.8.110.8 Best Path: False
Sub: 10.8.10.8 Best Path: False
Sub: 10.8.10.8 Best Path: False
Found Starting Network 10.10.11.0/24 10.8.42.8 Best Path: True
Sub: 10.8.42.8 Best Path: False
Sub: 10.8.42.8 Best Path: False
Sub: 10.9.42.8 Best Path: False
Found Starting Network 10.10.12.0/24 10.8.10.12 Best Path: False
Sub: 10.8.10.12 Best Path: False
Sub: 10.8.10.12 Best Path: True