snake_case

Snake case is the lower pattern with underscore _ delimiter.

Snake case is also known as lowercase_with_underscores.

History

Naming

The python standard library describes snake case as follows. ¹

The following naming styles are commonly distinguished.

…

• lower_case_with_underscores

Examples

Python and rust use snake case identifiers for function names.

def add_two(a):
    return a + 2

fn add_two(a: int) -> int {
    a + 2
}