67 lines
1.7 KiB
Python
67 lines
1.7 KiB
Python
from __future__ import absolute_import, division, unicode_literals
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from six import text_type
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from bisect import bisect_left
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from ._base import Trie as ABCTrie
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class Trie(ABCTrie):
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def __init__(self, data):
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if not all(isinstance(x, text_type) for x in data.keys()):
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raise TypeError("All keys must be strings")
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self._data = data
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self._keys = sorted(data.keys())
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self._cachestr = ""
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self._cachepoints = (0, len(data))
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def __contains__(self, key):
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return key in self._data
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def __len__(self):
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return len(self._data)
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def __iter__(self):
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return iter(self._data)
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def __getitem__(self, key):
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return self._data[key]
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def keys(self, prefix=None):
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if prefix is None or prefix == "" or not self._keys:
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return set(self._keys)
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if prefix.startswith(self._cachestr):
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lo, hi = self._cachepoints
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start = i = bisect_left(self._keys, prefix, lo, hi)
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else:
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start = i = bisect_left(self._keys, prefix)
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keys = set()
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if start == len(self._keys):
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return keys
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while self._keys[i].startswith(prefix):
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keys.add(self._keys[i])
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i += 1
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self._cachestr = prefix
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self._cachepoints = (start, i)
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return keys
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def has_keys_with_prefix(self, prefix):
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if prefix in self._data:
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return True
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if prefix.startswith(self._cachestr):
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lo, hi = self._cachepoints
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i = bisect_left(self._keys, prefix, lo, hi)
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else:
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i = bisect_left(self._keys, prefix)
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if i == len(self._keys):
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return False
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return self._keys[i].startswith(prefix)
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