| Pattern | Example | Meaning |
|---|
| Single Leading Underscore | _var | Naming convention indicating a name is meant for internal use. Generally not enforced by the Python interpreter (except in wildcard imports) and meant as a hint to the programmer only. |
| Single Trailing Underscore | var_ | Used by convention to avoid naming conflicts with Python keywords. |
| Double Leading Underscore | __var | Triggers name mangling when used in a class context. Enforced by the Python interpreter. |
| Double Leading and Trailing Underscore | __var__ | Indicates special methods defined by the Python language. Avoid this naming scheme for your own attributes. |
| Single Underscore | _ | Sometimes used as a name for temporary or insignificant variables (“don’t care”). Also: The result of the last expression in a Python REPL. |
The Meaning of Underscores in Python