如何从以逗号分隔的字符串中获取单个值

Question

我正在使用以下方式读取文件：

def readFile():
    file = open('Rules.txt', 'r')
    lines = file.readlines()
    for line in lines:
        rulesList.append(line)

规则列表：

['\n', "Rule(F1, HTTPS TCP, ['ip', 'ip'], ['www.google.ca', '8.8.8.8'], 443)\n", '\n', "Rule(F2, HTTPS TCP, ['ip', 'ip'], ['75.2.18.233'], 443)\n", '\n']

我的文件如下所示：

Rule(F1, HTTPS TCP, ['ip', 'ip'], ['www.google.ca', '8.8.8.8'], 443)

Rule(F2, HTTPS TCP, ['ip', 'ip'], ['ip'], 443)

我想将这些值提供给我创建的类

class Rule:
    def __init__(self, flowNumber, protocol, port, fromIP=[], toIP=[]):
        self.flowNumber = flowNumber
        self.protocol = protocol
        self.port = port
        self.fromIP = fromIP
        self.toIP = toIP

    def __repr__(self):
        return f'\nRule({self.flowNumber}, {self.protocol}, {self.fromIP}, {self.toIP}, {self.port})'

 newRule = Rule(currentFlowNum, currentProtocol, currentPort, currentFromIP, currentToIP)

获得如下输出：

[F1, HTTPS TCP, ['ip', 'ip'], ['www.google.ca', '8.8.8.8'], 443] 

或者能够将这些值分配给变量，例如：

currentFlowNum = F1, currentProtocol = 'HTTPS TCP' , currentPort = 443, currentFromIP = ['ip', 'ip'], currentToIP = ['www.google.ca', '8.8.8.8']

我试过：

for rule in rulesList:
        if rule !='\n':
            tmp = rule.split(',')
            print(tmp)

临时：

['Rule(F1', ' HTTPS TCP', " ['ip'", " 'ip']", " ['www.google.ca'", " '8.8.8.8']", ' 443)\n']
['Rule(F2', ' HTTPS TCP', " ['ip'", " 'ip']", " ['ip']", ' 443)\n']

有没有办法不分割 [] 之间的逗号，即我希望输出看起来像：

['Rule(F1', ' HTTPS TCP', " ['ip','ip']", " ['www.google.ca', '8.8.8.8']", ' 443)\n']
['Rule(F2', ' HTTPS TCP', " ['ip','ip']", " ['ip']", ' 443)\n']

Answer 1

如果您可以控制文件中数据的存储方式，并且可以用双引号 ( ') 替换单引号 ( ") 以使“列表”结构有效 JSON，则可以使用 RegExp 来实现此目的。

A word of caution: unless you are absolutely sure that the format you'll be reading will largely remain the same and is rather inflexible, you're better off storing this data in a more well-established format (as mentioned in the comments) like JSON, YAML, etc. There are so many edge cases that could happen here that rolling your own parser like this objectively suboptimal.

import re
import json

def readFile():
    file = open('Rules.txt', 'r')
    myRules = []
    for line in file.readlines():
        match = re.match(r'Rule\((?P<flow_number>[^,]+),\s(?P<protocol>[^,]+),\s(?P<from_ip>\[[^\]]+\]),\s(?P<to_ip>\[[^\]]+\]),\s(?P<port>[^,)]+)\)', line)
        if match:
          myRules.append(Rule(match.group('flow_number'), match.group('protocol'), match.group('port'), json.loads(match.group('from_ip')), json.loads(match.group('to_ip'))))

    return myRules


print(readFile())
# Returns:
# [
#  Rule(F1, HTTPS TCP, ['ip', 'ip'], ['www.google.ca', '8.8.8.8'], 443), 
#  Rule(F2, HTTPS TCP, ['ip', 'ip'], ['ip'], 443)]

^{Repl.it | Regex101}