Most Pythonic way to provide global configuration variables in config.py? [closed]

How about just using the built-in types like this:

config = {    "mysql": {        "user": "root",        "pass": "secret",        "tables": {            "users": "tb_users"        }        # etc    }}

You'd access the values as follows:

config["mysql"]["tables"]["users"]

If you are willing to sacrifice the potential to compute expressions inside your config tree, you could use YAML and end up with a more readable config file like this:

mysql:  - user: root  - pass: secret  - tables:    - users: tb_users

and use a library like PyYAML to conventiently parse and access the config file

I like this solution for small applications:

class App:  __conf = {    "username": "",    "password": "",    "MYSQL_PORT": 3306,    "MYSQL_DATABASE": 'mydb',    "MYSQL_DATABASE_TABLES": ['tb_users', 'tb_groups']  }  __setters = ["username", "password"]  @staticmethod  def config(name):    return App.__conf[name]  @staticmethod  def set(name, value):    if name in App.__setters:      App.__conf[name] = value    else:      raise NameError("Name not accepted in set() method")

And then usage is:

if __name__ == "__main__":   # from config import App   App.config("MYSQL_PORT")     # return 3306   App.set("username", "hi")    # set new username value   App.config("username")       # return "hi"   App.set("MYSQL_PORT", "abc") # this raises NameError

.. you should like it because:

• uses class variables (no object to pass around/ no singleton required),
• uses encapsulated built-in types and looks like (is) a method call on App,
• has control over individual config immutability, mutable globals are the worst kind of globals.
• promotes conventional and well named access / readability in your source code
• is a simple class but enforces structured access, an alternative is to use @property, but that requires more variable handling code per item and is object-based.
• requires minimal changes to add new config items and set its mutability.

--Edit--: For large applications, storing values in a YAML (i.e. properties) file and reading that in as immutable data is a better approach (i.e. blubb/ohaal's answer). For small applications, this solution above is simpler.

How about using classes?

# config.pyclass MYSQL:    PORT = 3306    DATABASE = 'mydb'    DATABASE_TABLES = ['tb_users', 'tb_groups']# main.pyfrom config import MYSQLprint(MYSQL.PORT) # 3306