Helpers

Various helper functions for working with Polars.

oi_tools.polars_helpers.clean_col_name(

name: str,

) → str

Normalize a column name to snake_case.

Parameters:

name (str) – Raw column name string.

Returns:

Cleaned column name with whitespace replaced by underscores, camelCase converted to snake_case, and non-alphanumeric characters replaced with underscores.

Return type:

str

oi_tools.polars_helpers.to_expr(

x: str | Expr | int | float,

) → Expr

Convert the input to a Polars expression.

Parameters:

x (str | Expr | int | float) – A Polars expression, column name string, or numeric literal.

Returns:

A Polars expression.

Return type:

pl.Expr

oi_tools.polars_helpers.to_masked_expr(

*xs: str | Expr | int | float,

) → Sequence[Expr]

Create a set of expressions with a standardized null mask.

All output expressions evaluate to null wherever any input expression is null.

Parameters:

*xs (str | Expr | int | float) – Expressions to mask.

Returns:

Expressions that evaluate to null when any input is null.

Return type:

Sequence[pl.Expr]

oi_tools.polars_helpers.to_selector(

x: Collection[str] | Selector,

) → Selector

Convert the input to a Polars selector.

Parameters:

x (Collection[str] | Selector) – A Polars selector or a collection of column names.

Returns:

A Polars column selector.

Return type:

cs.Selector