Creating a json file from user input in python 3.X

Question

I want to create a json file via input in my python script that looks like the below code. What is the best way to accomplish this?

File needed

[{
"device_type": "cisco_ios",
"ip": "192.168.1.1"
},
{
"device_type": "cisco_ios",
"ip": "192.168.1.2"
},
{
"device_type": "cisco_ios",
"ip": "192.168.1.3"
}]

I have a loop I created that works for list but I can't get it to work for the format above.

def dev_list():
devices = []
i = 0
while 1:
    i += 1
    device = input("Enter IP of Device %d: " % i)
    if device == "":
        break
    devices.append(device)

print(devices, "\n")
retry = input("Is your list correct? (y/n) ").strip().lower()
if retry == "no" or retry == "n":
    dev_list()
if retry == "yes" or retry == "y":
    print("\nScript will continue")
    return devices

Answer 1

Python has a built-in package called json, which can be use to work with JSON data. If you have a JSON string, you can parse it by using the json.loads() method. If you have a Python object, you can convert it into a JSON string by using the json.dumps() method.

Example:

import json

# a Python object (dict):
x = {
  "name": "John",
  "age": 30,
  "city": "New York"
}

# convert into JSON:
y = json.dumps(x)

# the result is a JSON string:
print(y) 

Answer 2

import json

data = {}  
data['product'] = []

data['product'].append({  
  'device_type': 'cisco_ios',
  'ip': '192.168.1.1'
})
data['product'].append({  
  'device_type': 'cisco_ios',
  'ip': '192.168.1.2'
})
data['product'].append({  
  'device_type': 'cisco_ios',
  'ip': '192.168.1.3'
})

with open('data.txt', 'w') as outfile:  
    json.dump(data, outfile)

Answer 3

Assuming you have devices already.

You can dump it to a file with a simple:

import json

with open("resultfile.json", "w") as f:
  json.dump(devices, f)

Using with syntax automatically closes the file after the block closes.

https://docs.python.org/3/library/json.html

So it will dump your python object to the file opened.