如何通过逐行读取文件来制作json字符串？

Question

I have a file like this:

machineA=1.2.3.4.5
machineB=2.5.7.8.9

I need to read above file and make a string like this for each line:

{"test":"hello world.","server":"machineA","ip":"1.2.3.4.5","reason":"data"}
{"test":"hello world.","server":"machineB","ip":"2.5.7.8.9","reason":"data"}

As you can see in my above json string only value of server and ip is changing and other remaining two keys, it's value stays same always. How can I generate a string like this for each line?

I am not able to figure out how to make correspoding json for each line and print them out on the console.

f = open('hosts.txt')
line = f.readline()
while line:
    print(line)
    machine=line.split("=")[0]
    ip=line.split("=")[1]

    # now how to make a json string for each line
    line = f.readline()
f.close()

Answer 1

I'd suggest making a dictionary then using the built in json module to convert it to a JSON string, because I find that cleaner to read.

import json

mydict = {
    "test": "hello world.",
    "server": machine,
    "ip": ip,
    "reason": "data"
 }
 json.dumps(mydict)

See Robᵩ's answer for how to do it without the json module

Answer 2

You don't have to use the JSON library just because the output format is JSON. Try one of these:

output_line = '{"test":"hello world.","server":"%s","ip":"%s","reason":"data"}'%(
    machine, ip)
output_line = '{{"test":"hello world.","server":"{}","ip":"{}","reason":"data"}'.format(
    machine, ip)
output_line = f'{{"test":"hello world.","server":"{machine}","ip":"{ip}","reason":"data"}'

Note that the final line only works on recent versions of Python3.