towhee.functional.mixins.safe.SafeMixin

class towhee.functional.mixins.safe.SafeMixin

Bases: object

Mixin for exception safety.

Methods

drop_empty	Unbox Option values and drop Empty.
exception_safe	Making the data collection exception-safe by warp elements with Option.
fill_empty	Unbox Option values and fill Empty with default values.
safe	Shortcut for exception_safe.

drop_empty(callback: Callable = None) → DataCollection

Unbox Option values and drop Empty.

Parameters:

callback (Callable) – handler for empty values;

Returns:

A DataCollection that drops empty values;

Return type:

DataCollection

Examples:

>>> from towhee import DataCollection
>>> dc = DataCollection.range(5)
>>> dc.safe().map(lambda x: x / (0 if x == 3 else 2)).drop_empty().to_list()
[0.0, 0.5, 1.0, 2.0]

Get inputs that case exceptions:

>>> exception_inputs = []
>>> result = dc.safe().map(lambda x: x / (0 if x == 3 else 2)).drop_empty(lambda x: exception_inputs.append(x.get().value))
>>> exception_inputs
[3]

exception_safe()

Making the data collection exception-safe by warp elements with Option.

Examples:

1. Exception breaks pipeline execution:

>>> from towhee import DataCollection
>>> dc = DataCollection.range(5)
>>> dc.map(lambda x: x / (0 if x == 3 else 2)).to_list()
Traceback (most recent call last):
ZeroDivisionError: division by zero

2. Exception-safe execution

>>> dc.exception_safe().map(lambda x: x / (0 if x == 3 else 2)).to_list()
[Some(0.0), Some(0.5), Some(1.0), Empty(), Some(2.0)]

>>> dc.exception_safe().map(lambda x: x / (0 if x == 3 else 2)).filter(lambda x: x < 1.5).to_list()
[Some(0.0), Some(0.5), Some(1.0), Empty()]

>>> dc.exception_safe().map(lambda x: x / (0 if x == 3 else 2)).filter(lambda x: x < 1.5, drop_empty=True).to_list()
[Some(0.0), Some(0.5), Some(1.0)]

fill_empty(default: Any = None) → DataCollection

Unbox Option values and fill Empty with default values.

Parameters:

default (Any) – default value to replace empty values;

Returns:

data collection with empty values filled with default;

Return type:

DataCollection

Examples:

>>> from towhee import DataCollection
>>> dc = DataCollection.range(5)
>>> dc.safe().map(lambda x: x / (0 if x == 3 else 2)).fill_empty(-1.0).to_list()
[0.0, 0.5, 1.0, -1.0, 2.0]

safe()

Shortcut for exception_safe.