Created
February 2, 2016 03:38
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| #!/usr/bin/env python | |
| # -*- coding: utf-8 -*- | |
| import unittest | |
| class ListDict(list): | |
| """ List of dicts with rapid is-element-of operation for the whole thing. | |
| (e.g. `(k, v) in list_dict`) | |
| Keys and values must be hashable. | |
| """ | |
| def __init__(self, iterable=None): | |
| if iterable is not None: | |
| iterable = (_LD_Dict(self, item) for item in iterable) | |
| else: | |
| iterable = [] | |
| self._super = super(ListDict, self) | |
| self._super.__init__(iterable) | |
| self.dirty = True | |
| @property | |
| def entries(self): | |
| if self.dirty: | |
| self._update_entries() | |
| return self._entries | |
| def _update_entries(self): | |
| if not self.dirty: | |
| return | |
| self._entries = set().union(*(d.entries for d in self)) | |
| self.dirty = False | |
| def __setitem__(self, key, value): | |
| self._super.__setitem__(key, _LD_Dict(self, value)) | |
| self.dirty = True | |
| def append(self, value): | |
| self._super.append(_LD_Dict(self, value)) | |
| self.dirty = True | |
| def extend(self, values): | |
| append = self.append # Does the interpreter already do this optimization? | |
| for value in values: | |
| append(value) | |
| def __getitem__(self, key): | |
| return self._super.__getitem__(key) | |
| def __delitem(self, key): | |
| self._super.__delitem__(key) | |
| self.dirty = True | |
| def __contains__(self, value): | |
| return value in self.entries | |
| def __repr__(self): | |
| return '{%s}.entries = %s' % (list(self), self.entries) | |
| class _LD_Dict(dict): | |
| def __init__(self, parent, *args, **kwargs): | |
| self.parent = parent | |
| self._super = super(_LD_Dict, self) | |
| self._super.__init__(*args, **kwargs) | |
| self.entries = set(self.iteritems()) | |
| def __setitem__(self, key, value): | |
| try: | |
| self.entries.remove((key, self[key])) | |
| except KeyError: | |
| pass | |
| self.entries.add((key, value)) | |
| self._super.__setitem__(key, value) | |
| self.parent.dirty = True | |
| def __delitem__(self, key): | |
| self.entries.remove((key, self[key])) | |
| self.parent.dirty = True | |
| self._super.__delitem__(key) | |
| _test_dict = {'blah': 'qwer'} | |
| _test_pair = ('blah', 'qwer') | |
| class Test_ListDict(unittest.TestCase): | |
| def test_init(self): | |
| ld = ListDict([_test_dict]) | |
| self.assertIn(_test_pair, ld) | |
| def test_setitem(self): | |
| ld = ListDict([{'foo': 'bar'}]) | |
| ld[0] = _test_dict | |
| self.assertIn(_test_pair, ld) | |
| def test_delitem(self): | |
| ld = ListDict([_test_dict]) | |
| del ld[0] | |
| self.assertSetEqual(ld.entries, set()) | |
| def test_append(self): | |
| ld = ListDict() | |
| ld.append(_test_dict) | |
| self.assertIn(_test_pair, ld) | |
| def test_extend(self): | |
| ld = ListDict() | |
| ld.extend([_test_dict]) | |
| self.assertIn(_test_pair, ld) | |
| def test_inner_setitem(self): | |
| ld = ListDict([]) | |
| ld.append({}) | |
| ld[0]['blah'] = 'qwer' | |
| self.assertIn(_test_pair, ld) | |
| def test_inner_delitem(self): | |
| ld = ListDict([_test_dict]) | |
| del ld[0]['blah'] | |
| self.assertSetEqual(ld.entries, set()) | |
| def main(): | |
| unittest.main() | |
| if __name__ == '__main__': | |
| main() |
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