Option

Option#

Option module.

Contains a collection of static methods (functions) for operating on options. All functions takes the source as the last curried argument, i.e all functions returns a function that takes the source sequence as the only argument.

Nothing: Option[Any] = Option(none=None)#

Singleton Nothing object.

Since Nothing is a singleton it can be tested e.g using is:

>>> if xs is Nothing:
...     return True

class Option(**kwargs: Any)#

Option class.

static Nothing() → Option[_TSourceOut]#: Create a None option.

static Some(value: _TResult) → Option[_TResult]#: Create a Some option.

bind(mapper: Callable[[_TSourceOut], Option[_TResult]]) → Option[_TResult]#

Bind option.

Applies and returns the result of the mapper if the value is Some. If the value is Nothing then Nothing is returned.

Parameters:: mapper – A function that takes the value of type TSource from an option and transforms it into an option containing a value of type TResult.
Returns:: An option of the output type of the mapper.

default_value(value: _TSource) → _TSourceOut | _TSource#

Get with default value.

Gets the value of the option if the option is Some, otherwise returns the specified default value.

default_with(getter: Callable[[], _TSource]) → _TSourceOut | _TSource#

Get with default value lazily.

Gets the value of the option if the option is Some, otherwise returns the value produced by the getter

dict() → _TSourceOut | None#: Returns a json string representation of the option.

filter(predicate: Callable[[_TSourceOut], bool]) → Option[_TSourceOut]#

Filter option.

Returns the input if the predicate evaluates to true, otherwise returns Nothing.

is_none() → bool#: Returns true if the option is Nothing.

is_some() → bool#: Returns true if the option is not Nothing.

map(mapper: Callable[[_TSourceOut], _TResult]) → Option[_TResult]#

Map option.

Applies the mapper to the value if the option is Some, otherwise returns Nothing.

map2(mapper: Callable[[_TSourceOut, _T2], _TResult], other: Option[_T2]) → Option[_TResult]#

Map2 option.

Applies the mapper to the values if both options are Some, otherwise returns Nothing.

static of_obj(value: _TSource) → Option[_TSource]#: Convert object to an option.

static of_optional(value: _TSource | None) → Option[_TSource]#: Convert optional value to an option.

static of_result(result: Result[_TSource, Any]) → Option[_TSource]#: Convert result to an option.

or_else(if_none: Option[_TSourceOut]) → Option[_TSourceOut]#: Returns option if it is Some, otherwise returns if_one.

or_else_with(if_none: Callable[[], Option[_TSourceOut]]) → Option[_TSourceOut]#

Or-else-with.

Returns option if it is Some, otherwise evaluates the given function and returns the result.

starmap(mapper: Callable[[Unpack], _TResult]) → Option[_TResult]#

Starmap option.

Applies the mapper to the values if the option is Some, otherwise returns Nothing. The tuple is unpacked before applying the mapper.

to_list() → list[_TSourceOut]#: Convert option to list.

to_optional() → _TSourceOut | None#: Convert option to an optional.

to_result(error: _TError) → Result[_TSourceOut, _TError]#: Convert option to a result.

to_result_with(error: Callable[[], _TError]) → Result[_TSourceOut, _TError]#: Convert option to a result.

to_seq() → Seq[_TSourceOut]#: Convert option to sequence.

property value: _TSourceOut#

Returns the value wrapped by the option.

A ValueError is raised if the option is Nothing.

Some(value: _T1) → Option[_T1]#: Create a Some option.

bind(option: Option[_TSource], mapper: Callable[[_TSource], Option[_TResult]]) → Option[_TResult]#

Bind option.

Applies and returns the result of the mapper if the value is Some. If the value is Nothing then Nothing is returned.

Parameters:

option – Source option to bind.
mapper – A function that takes the value of type _TSource from an option and transforms it into an option containing a value of type TResult.

Returns:

A partially applied function that takes an option and returns an option of the output type of the mapper.

default_arg(value: Option[_TSource], default_value: _T1) → _TSource | _T1#

Specify default argument.

Used to specify a default value for an optional argument in the implementation of a function. Same as default_value, but “uncurried” and with the arguments swapped.

default_value(option: Option[_TSource], value: _T1) → _TSource | _T1#

Get value or default value.

Gets the value of the option if the option is Some, otherwise returns the specified default value.

default_with(getter: Callable[[], _TSource]) → Callable[[Option[_TSource]], _TSource]#

Get with default value lazily.

Gets the value of the option if the option is Some, otherwise returns the value produced by the getter

of_obj(value: Any) → Option[Any]#

Convert object to an option.

Convert a value that could be None into an Option value.

Parameters:: value – The input object.
Returns:: The result option.

of_optional(value: _TSource | None) → Option[_TSource]#

Convert an optional value to an option.

Parameters:: value – The input optional value.
Returns:: The result option.

or_else(option: Option[_TSource], if_none: Option[_TSource]) → Option[_TSource]#: Returns option if it is Some, otherwise returns if_none.

to_optional(value: Option[_TSource]) → _TSource | None#

Convert an option value to an optional.

Parameters:: value – The input option value.
Returns:: The result optional.

Option

Contents

Option#