python - Python，在文本文件中查找行，然后跳转到下一个“要查找的字符串”

Question

要搜索的字符串：

filecontent = policy-map PM_QOS_C_V-50-50-0-0
     class CM_QOS_C_VOICE
      priority level 1
      police cir percent 9
     class CM_QOS_C_VIDEO
      priority level 2 percent 15
     class CM_QOS_C_ROUTING
      bandwidth remaining percent 1 
      police cir percent 6
     class CM_QOS_C_NETMGT
      bandwidth remaining percent 1 
      police cir percent 6
      set mpls experimental topmost 7
     class CM_QOS_C_CALLSIG
      bandwidth remaining percent 1 
      set mpls experimental topmost 7
      police cir percent 6
     class CM_QOS_C_SRV
      bandwidth remaining percent 7 
      queue-limit 4096 packets
      police cir percent 20
     class CM_QOS_C_PRIORITY
      bandwidth remaining percent 7 
      queue-limit 64 packets
      police cir percent 30
     ....

qos = {'VOICE': {'remainingbwspeed': 990.0,
             'remainingpercent': 22,
             'string': '#VOICE#'},
 'VIDEO': {'remainingbwspeed': 405.0,
              'remainingpercent': 9,
              'string': '#VIDEO#'}}....

我想遍历获取的文本文件并将文本文件中的“百分比”值替换为“新”值。到目前为止我做了：

• 逐行打开文件，在字典中找到键并打印下一行。

我找不到什么：

• 打开文件，遍历文件直到第一个键，跳转到第一个百分比，然后替换带宽剩余值。

到目前为止我使用的代码：[上面的字符串是文件的内容，snippit]

with open("./playbooks/qos/policy_map_PM_QOS_C_V-50-50-0-0.cfg", "r") as file:
    for i, line in enumerate(file):
        for key, value in qos.items():
            pattern = re.compile(key)
            for match in re.finditer(pattern, line):
                print(line)
                line1=file.readline()
                line2=file.readline()
                print(line1)
                print(line2)

但这似乎弄乱了迭代器。

Answer 1

我会这样做（只要你的正则表达式是字符串）：

with open("./playbooks/qos/policy_map_PM_QOS_C_V-50-50-0-0.cfg", "r") as file:
    line = True
    while line:
        line = file.readline()
        for key in qos.keys():
            if key in line:
                print(line)
                line1=file.readline()
                line2=file.readline()
                print(line1)
                print(line2)
                break # otherwise it'll continue checking the other keys after one is found, if you want that functionality then remove this break