| #!/usr/bin/env python |
| #coding:utf-8 |
| # Author: mozman -- <mozman@gmx.at> |
| # Purpose: TreeSlice |
| # Created: 11.04.2011 |
| # Copyright (c) 2010-2013 by Manfred Moitzi |
| # License: MIT License |
| |
| |
| class TreeSlice(object): |
| __slots__ = ['_tree', '_start', '_stop'] |
| |
| def __init__(self, tree, start, stop): |
| self._tree = tree |
| self._start = start |
| self._stop = stop |
| |
| def __repr__(self): |
| tpl = "%s({%s})" % (self._tree.__class__.__name__, '%s') |
| return tpl % ", ".join( ("%r: %r" % item for item in self.items()) ) |
| |
| def __contains__(self, key): |
| if self._inrange(key): |
| return key in self._tree |
| else: |
| return False |
| |
| def _inrange(self, key): |
| if self._start is not None and key < self._start: |
| return False |
| if self._stop is not None and key >= self._stop: |
| return False |
| return True |
| |
| def __getitem__(self, key): |
| if isinstance(key, slice): |
| return self._subslice(key.start, key.stop) |
| if self._inrange(key): |
| return self._tree[key] |
| else: |
| raise KeyError(key) |
| |
| def _subslice(self, start, stop): |
| def newstart(): |
| if start is None: |
| return self._start |
| elif self._start is None: |
| return start |
| else: |
| return max(start, self._start) |
| |
| def newstop(): |
| if stop is None: |
| return self._stop |
| elif self._stop is None: |
| return stop |
| else: |
| return min(stop, self._stop) |
| |
| return TreeSlice(self._tree, newstart(), newstop()) |
| |
| def keys(self): |
| return self._tree.keyslice(self._start, self._stop) |
| __iter__ = keys |
| |
| def values(self): |
| return self._tree.valueslice(self._start, self._stop) |
| |
| def items(self): |
| return self._tree.itemslice(self._start, self._stop) |
