Recipe 389639 revision 1

import copy

class DefaultDict(dict):
    """Dictionary with a default value for unknown keys."""
    def __init__(self, default):
        self.default = default

    def __getitem__(self, key):
        if key in self: 
            return self.get(key)
        else:
            ## Need copy in case self.default is something like []
            return self.setdefault(key, copy.deepcopy(self.default))

    def __copy__(self):
        copy = DefaultDict(self.default)
        copy.update(self)
        return copy

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History

• revision 1 (19 years ago)