ping 多个 ip 并写入 JSON 文件 python

Question

我正在 ping 局域网中的多个 ip 以检查它是否处于活动状态。代码将根据计划每分钟运行一次。对于 ping 多个 ip，我使用了多处理。它在多处理的帮助下做得很好。同时，我想在 ping 之后将 ping 结果写入 json 文件。但是当写入 JSON 文件时，它只写入最后一个 ip 的输出。我想要所有三个。 有没有办法做到这一点

这是示例代码：

import json
from multiprocessing import Pool
import subprocess
from datetime import datetime
timestamp = datetime.now().strftime("%B %d %Y, %H:%M:%S")
hosts =  ["192.168.1.47","192.168.1.42"]
count = 1
wait_sec = 1
n = len(hosts)
def main(hosts):
    p = Pool(processes= n)
    result = p.map(beat, hosts)
def beat(hosts):
    #Name for the log file
    name = 'icmp.json'
    ip4write(hosts, name)
def ip4write(hosts, name):
    global ip4a
    ip4a = hosts
    ipve4(hosts, name)
    write(hosts, name)
def ipve4(hosts, name):
    global u
    status, result = subprocess.getstatusoutput("ping -c1 -w2 " + str(ip4a))
    if status == 0:
        print(str(ip4a) + " UP")
        u = " UP"
def write(hosts, name):
    text_file = open(name, "a+")
    with open(name) as json_file:
      try:
          data = json.load(json_file)
      except:
          data = {}
      with open(name, 'w') as outfile:
        data[timestamp] = {
          'monitor.ip':str(hosts),
          'monitor.status': u
        }
        print(data)
        json.dump(data, outfile)
        print('Data written')
    text_file.close()
main(hosts)

JSON 文件中的输出：

{"February 15 2019, 16:38:12": {"monitor.status": " UP", "monitor.ip": "192.168.1.42"}}

我需要的输出：

{"February 15 2019, 16:38:12": {"monitor.ip": "192.168.1.47", "monitor.status": " UP"}, "February 15 2019, 16:38:12": {"monitor.ip": "192.168.1.42", "monitor.status": " UP"}}

Answer 1

要继续向现有文件添加内容而不覆盖现有内容，您应该以“追加”模式打开。在您的代码中，您以“写入”模式打开。这将打开文件进行写入，但会覆盖现有内容。

具体来说，代码中的这一行：

with open(name, 'w') as outfile:

您应该将打开模式从写入 ('w') 更改为附加 ('a')。

with open(name, 'a') as outfile:

如果这能解决您的问题，请告诉我。

Answer 2

以下是代码的精简版：

import os
from multiprocessing import Pool
import json
import datetime
import time

hosts = ["192.168.1.47", "8.8.8.8"]
MAX_NUMBER_OF_STATUS_CHECKS = 2
FILE_NAME = 'hosts_stats.json'


#
# counter and sleep were added in order to simulate scheduler activity  
#

def ping(host):
    status = os.system('ping  -o -c 3 {}'.format(host))
    return datetime.datetime.now().strftime("%B %d %Y, %H:%M:%S"), {"monitor.ip": host,
                                                                "monitor.status": 'UP' if status == 0 else 'DOWN'}


if __name__ == "__main__":
    p = Pool(processes=len(hosts))
    counter = 0
    if not os.path.exists(FILE_NAME):
        with open(FILE_NAME, 'w') as f:
            f.write('{}')
    while counter < MAX_NUMBER_OF_STATUS_CHECKS:
        result = p.map(ping, hosts)
        with open(FILE_NAME, 'rb+') as f:
            f.seek(-1, os.SEEK_END)
            f.truncate()
            for entry in result:
                _entry = '"{}":{},\n'.format(entry[0], json.dumps(entry[1]))
                f.writelines(_entry)
             f.write('}')
        counter += 1
        time.sleep(2)