persistent package provides two simple collections that are
persistent and keep track of when they are mutated in place.
- class persistent.mapping.PersistentMapping(dict=None, /, **kwargs)
A persistent wrapper for mapping objects.
This class allows wrapping of mapping objects so that object changes are registered. As a side effect, mapping objects may be subclassed.
A subclass of PersistentMapping or any code that adds new attributes should not create an attribute named _container. This is reserved for backwards compatibility reasons.
Remove all data from this dictionary.
Changed in version 4.5.2: If there was nothing to remove, this object is no longer marked as modified.
- pop(k[, d]) v, remove specified key and return the corresponding value.
If key is not found, d is returned if given, otherwise KeyError is raised.
Remove an item.
Changed in version 4.5.2: No longer marks this object as modified if it was empty and an exception raised.
- setdefault(k[, d]) D.get(k,d), also set D[k]=d if k not in D
- update([E, ]**F) None.
Changed in version 4.5.2: Now accepts arbitrary keyword arguments. In the special case of a keyword argument named
bthat is a dictionary, the behaviour will change.
- class persistent.list.PersistentList(initlist=None)
A persistent wrapper for list objects.
Mutating instances of this class will cause them to be marked as changed and automatically persisted.
Changed in version 4.5.2: Using the clear method, or deleting a slice (e.g.,
del inst[x:x]) now only results in marking the instance as changed if it actually removed items.
S.append(value) – append value to the end of the sequence
Remove all items from the list.
Changed in version 4.5.2: Now marks the list as changed.
S.extend(iterable) – extend sequence by appending elements from the iterable
- insert(i, item)
S.insert(index, value) – insert value before index
- pop([index]) item -- remove and return item at index (default last).
Raise IndexError if list is empty or index is out of range.
S.remove(value) – remove first occurrence of value. Raise ValueError if the value is not present.
S.reverse() – reverse IN PLACE