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56. Configuration Files

1. Introduction​

Configuration files store program settings. Python supports multiple formats like .ini, .yaml, .json, and environment variables.

2. Using INI Files with configparser​

import configparser

config = configparser.ConfigParser()
config.read("settings.ini")

print(config["DEFAULT"]["username"])

Example settings.ini:

[DEFAULT]
username = admin
password = secret

3. Writing INI Files​

config["NEW"] = {"key": "value"}
with open("settings.ini", "w") as f:
    config.write(f)

4. JSON Config Files​

import json
with open("config.json") as f:
    cfg = json.load(f)
print(cfg)

5. YAML Config Files (via PyYAML)​

import yaml
with open("config.yaml") as f:
    cfg = yaml.safe_load(f)
print(cfg)

6. Best Practices​

  • Keep secrets (like passwords) out of config files.
  • Use environment variables for sensitive info.
  • Document your config structure.

7. Next Steps​

✅ You now know how to use configuration files.
Next: Environment variables.