Module motor_odm.helpers

This module contains various supporting functions that can be used independently of the Motor-ODM framework. Some of these utilities can be found in similar form in other packages or frameworks and are adapted here to reduce the number of dependencies.

motor_odm.helpers.inherit_class(name: str, self: Optional[T], parent: T, merge: Iterable[str] = None) → T

Performs a pseudo-inheritance by creating a new class that inherits from self and parents. This is useful to support intuitive inheritance on inner classes (typically named Meta).

Note that this method neither returns self nor any of the parents but a new type that inherits from both.

Parameters

• name – The name of the newly created type.

• self – The primary base class (fields in this class take preference over the parents’ fields.

• parent – The secondary base class (a pseudo-parent of self).

• merge – A list of fields that should not be replaces during inheritance but merged. This only works for some types.

Returns

A new type inheriting from self and parents.

motor_odm.helpers.merge_values(value1: Any, value2: Any) → Any

Merges two values.

This method works only for specific collection types (namely lists, dicts and sets). For other values a ValueError is raised.

The type of the resulting value is determined by the type of value2, however value1 may override some of the contents in value2 (e.g. replace values for dict keys).

motor_odm.helpers.monkey_patch(cls: Union[type, module], name: Optional[str] = None) → Callable[[C], C]

Monkey patches class or module by adding to it decorated function. Anything overwritten can be accessed via a .original attribute of the decorated object.

Parameters

• cls – The class or module to be patched.

• name – The name of the attribute to be patched.

Returns

A decorator that monkey patches cls.name and returns the decorated function.