Recommended way to store users,db credentials in a Python project?

[PrateekG]

I am working on a project where I am storing DB and users's credentials inside python code.
For example I have a script db.py which do crud operations and I am storing credential in this script as below-

credentials = {
"UAT": {
    "host": 'UAT_HOST',
    "port": UAT_PORT_Num,
    "read_db": 'SCHEMA_1',
    "write_db": 'SCHEMA_2',
    "user": 'UAT_USER',
    "password": 'UAT_PASSWORD'
},
"S3": {
    "KEY": 'S3_KEY',
    "SECRET": 'S3_SECRET_KEY'
}
}

Similarly I have a script merchant.py where I am using credentials like-

MERCHANT_ID = 1
STORE_ID = '1'
CATEGORY_ID = 123
URL = 'http://example.com'
environment = 'UAT'

I need to move above credentials in a secure place but I don't have any idea how to do that.
I am using Python3.6,Mysql.
Can you please suggest me what will be the standard approach?