30 lines
967 B
Python
30 lines
967 B
Python
import dataclasses
|
|
import typing
|
|
|
|
|
|
DCInst = typing.TypeVar('T')
|
|
|
|
|
|
def nested_replace(obj: DCInst, new_values: typing.Dict[str, typing.Any]) -> DCInst:
|
|
"""
|
|
Replace an attribute on a dataclass, much like dataclasses.replace, except it
|
|
supports nested replacement definitions. For example:
|
|
|
|
>>> new_obj = nested_replace(obj, {'attr1.sub_attr2.sub_sub_attr3': 4})
|
|
>>> new_obj.attr1.sub_attr2.sub_sub_attr3
|
|
4
|
|
|
|
"""
|
|
new_inst = obj
|
|
for name, value in new_values.items():
|
|
if '.' in name:
|
|
# Recurse into the desired name and come out with a top-level
|
|
# dataclass which has been updated appropriately.
|
|
name, remainder = name.split('.', 1)
|
|
value = nested_replace(
|
|
getattr(new_inst, name),
|
|
{remainder: value}
|
|
)
|
|
# We have a plain old name. So set it.
|
|
new_inst = dataclasses.replace(new_inst, **{name: value})
|
|
return new_inst
|