Python - 如何比较两个列表的内容在一个字符串中

Question

我需要比较列表“present”的所有项目都在字符串“line”中，并且列表“absent”的所有元素都不在字符串“line”中

因此，拥有 2 个列表

present = ['SYN', 'ACK']
absent = ['RST', 'FIN']

还有一个包含所有 TCP 标志的文件： https://github.com/robcowart/elastiflow/blob/master/logstash/elastiflow/dictionaries/tcp_flags.yml

"...
"12": RST-PSH
"13": FIN-RST-PSH
"14": SYN-RST-PSH
"15": FIN-SYN-RST-PSH
"16": ACK
"17": FIN-ACK
"18": SYN-ACK
"19": FIN-SYN-ACK
"20": RST-ACK
"21": FIN-RST-ACK
"22": SYN-RST-ACK
"23": FIN-SYN-RST-ACK
..."

如果“present”的所有元素都存在于该行中并且“absent”的所有元素都不存在于该行中，我将逐行读取文件，然后打印该行

我该怎么做？ 我想象递归或理解，但我找不到方法。 谢谢

Answer 1

for line in csv_reader:
    # parse the line and store the flags into a list
    # flags = line.split...

    # the logic to check for present and absent
    is_present = all(elem in flags for elem in present)
    is_absent = not any(elem in flags for elem in absent)
    if is_present and is_absent:
        print(line)

Answer 2

line="abcee"
present=['abc','cde','fgh']
absent=['bla','ghj']
def AllInLine():
    for i in present:
        if i not in line:
            return False;
    return True;
def NoneInLine():
    for i in absent:
        if i in line:
            return False;
    return True;

然后如果两个函数都返回 true 你可以打印该行

Answer 3

这是您可以尝试的方法。 它使用requests从 GitHub 下载原始 YAML 文件，使用PyYAML解析 YAML ，然后使用all()检查每个项目是否absent和present线。

YAML 文件也以块的形式下载，以防它变大。 无论如何，当通过 HTTP 下载文件时，这是一个很好的做法。

演示：

from pathlib import Path
from requests import get
from yaml import safe_load, YAMLError

def download_file(url, chunk_size=1024):
    with get(url, stream=True) as req:
        filename = Path(url).name
        with open(filename, mode="wb") as f:
            for chunk in req.iter_content(chunk_size=chunk_size):
                if chunk:
                    f.write(chunk)

def parse_yaml_file(path):
    with open(path) as f:
        try:
            yaml_file = safe_load(f)
            return yaml_file
        except YAMLError as ex:
            print(ex)

if __name__ == "__main__":
    present = ['SYN', 'ACK']
    absent = ['RST', 'FIN']

    yaml_file = download_file("https://raw.githubusercontent.com/robcowart/elastiflow/master/logstash/elastiflow/dictionaries/tcp_flags.yml")

    data = parse_yaml_file(yaml_file)

    for number, line in data.items():
        if all(p in line for p in present) and all(a not in line for a in absent):
            print(f"{number}: {line}")

Output：

18: SYN-ACK
26: SYN-PSH-ACK
50: SYN-ACK-URG
58: SYN-PSH-ACK-URG
82: SYN-ACK-ECE
90: SYN-PSH-ACK-ECE
114: SYN-ACK-URG-ECE
122: SYN-PSH-ACK-URG-ECE
146: SYN-ACK-CWR
154: SYN-PSH-ACK-CWR
178: SYN-ACK-URG-CWR
186: SYN-PSH-ACK-URG-CWR
210: SYN-ACK-ECE-CWR
218: SYN-PSH-ACK-ECE-CWR
242: SYN-ACK-URG-ECE-CWR
250: SYN-PSH-ACK-URG-ECE-CWR

注意：上面可能需要对您的场景进行更多的错误检查，但它显示了总体思路。