Mutate nested Python objects using a method inspired by SolidJS's setState function for updating stores.
https://www.solidjs.com/docs/latest/api#updating-stores
update lists by index
>>> from pymutator import mutate >>> mutate([1, 2, 3, 4, 5], 3, 'D') [1, 2, 3, 'D', 5]
update lists by list of indices
>>> mutate([1, 2, 3, 4, 5], [1, 3], 'D') [1, 'D', 3, 'D', 5]
update lists by filter predicate
>>> mutate([1, 2, 3, 4, 5], lambda i: i%2, 'odd') ['odd', 2, 'odd', 4, 'odd']
update list with computed value
>>> mutate([1, 2, 3, 4, 5], 3, lambda i: f'D{i}') [1, 2, 3, 'D4', 5]
update dict
>>> mutate({'a': 1, 'b': 2, 'c': 3}, 'b', 'B') {'a': 1, 'b': 'B', 'c': 3}
>>> mutate({'a': 1, 'b': 2, 'c': 3}, b='B') {'a': 1, 'b': 'B', 'c': 3}
>>> mutate({'a': 1, 'b': 2, 'c': 3}, {'b': 'B'}) {'a': 1, 'b': 'B', 'c': 3}
>>> mutate({'a': 1, 'b': 2, 'c': 3}, ['b', 'x'], 'B') {'a': 1, 'b': 'B', 'c': 3, 'x': 'B'}
update dict with filter predicate
>>> mutate({'a': 1, 'b': 2, 'c': 3}, lambda i: i%2, 'odd') {'a': 'odd', 'b': 2, 'c': 'odd'}
update dict with computed value
>>> mutate({'a': 1, 'b': 2, 'c': 3}, 'b', lambda i: f'B{i}') {'a': 1, 'b': 'B2', 'c': 3}
update object
>>> class O: ... def __init__(self): self.a = 1 >>> o = O() >>> mutate(o, 'a', 2) and o.a 2
>>> mutate(o, a=3) and o.a 3
>>> mutate(o, {'a': 4}) and o.a 4
>>> mutate(o, 'a', lambda i: i+1) and o.a 5
updating nested objects
>>> store = { ... 'todos': [ ... {'task': 'Finish work', 'completed': False}, ... {'task': 'Go grocery shopping', 'completed': False}, ... {'task': 'Make dinner', 'completed': False}, ... ] ... }
>>> mutate(store, 'todos', [0, 2], 'completed', True) {'todos': [{'task': 'Finish work', 'completed': True}, {'task': 'Go grocery shopping', 'completed': False}, {'task': 'Make dinner', 'completed': True}]}
>>> mutate(store, 'todos', lambda todo: todo['completed'], ... 'task', lambda t: t + '!') {'todos': [{'task': 'Finish work!', 'completed': True}, {'task': 'Go grocery shopping', 'completed': False}, {'task': 'Make dinner!', 'completed': True}]}
$ pytest