Python: Underscores

Single Leading Underscore

• A PEP8 convention to show that a variable or method is intended for internal use only.

Double Leading Underscore

• The Python interpreter mangles names with double leading underscores to prevent collisions with subclasses.

Single Trailing Underscore

• A PEP8 convention for the use of reserved keywords as variable or method names.

Double Trailing Underscore

• Used for dunder methods.
• Dunder methods are in-built methods such as __init__.