Source code for asab.pdict

import collections
import os
import shelve

[docs]class PersistentDict(dict): """ The persistent dictionary works as the regular Python dictionary but the content of the dictionary is stored in the file. You cat think of a ``PersistentDict`` as a simple `key-value store <>`_. It is not optimized for a frequent access. This class provides common ``dict`` interface. *Warning*: You must explicitly `load()` and `store()` content of the dictionary *Warning*: You can only store objects in the persistent dictionary that are serializable. """ def __init__(self, path): super().__init__() # Create directory, if needed dirname = os.path.dirname(path) if not os.path.isdir(dirname): os.makedirs(dirname) self._path = path def __delitem__(self, key): super().__delitem__(key) with as d: del d[key]
[docs] def load(self) -> None: """ Load content of file as dictionary. """ with as d: for key, value in d.items(): self[key] = value
[docs] def store(self) -> None: """ Explicitly store content of persistent dictionary to file """ with as d: for key, value in self.items(): d[key] = value
[docs] def update(self, other=(), **kwds) -> None: """ Update D from mapping/iterable E and F. * If E present and has a .keys() method, does: for k in E: D[k] = E[k] * If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v * In either case, this is followed by: for k, v in F.items(): D[k] = v Inspired by a """ if isinstance(other, collections.Mapping): for key in other: self[key] = other[key] elif hasattr(other, "keys"): for key in other.keys(): self[key] = other[key] else: for key, value in other: self[key] = value for key, value in kwds.items(): self[key] = value