Using JSON config files in Python.

Let’s assume your app needs variables width and height and you want your users to be able to change the values in a config file.

Step 1: Create JSON config file

• Create empty text file 'config.JSON'
• Add a width and height value in JSON notation like this:

{
  "width" : 1024,
  "height" : 768
}

Step 2: Create Python script

• Create empty text file 'loadconfig.py' and put it in the same folder as 'config.JSON'

To open 'config.JSON', you can use Pythons open function. To use the json load function, you need to import the json module. json.load returns a dictionary that can be accessed by its keys. The syntax is data['width'].

Here is the code:

import json

with open('config.json') as config_file:
data = json.load(config_file)

width = data['width']
height = data['height']
print(width)
print(height)

Execute

Open a terminal and execute the script with 'python loadconfig.py'. The result should look like this:

1024
768