class ExponentiallyDecayingReservoir(object):
def __init__(self, size=_DEFAULT_SIZE, alpha=_DEFAULT_ALPHA):
self.size = size
self.alpha = alpha
self.start_time = time()
self.next_scale_time = self.start_time + _RESCALE_THRESHOLD
self.values = SortedDict()
def _rescale_if_needed(self):
now = time()
if now > self.next_scale_time:
self.next_scale_time = now + _RESCALE_THRESHOLD
old_start_time = self.start_time
self.start_time = now
scaling_factor = exp(-self.alpha * (self.start_time - old_start_time))
self.values = SortedDict(
(priority * scaling_factor, _WeightedSample(sample.value, sample.weight * scaling_factor))
for priority, sample in self.values.items()
)
def update(self, value):
self._rescale_if_needed()
timestamp = time()
item_weight = exp(self.alpha * (timestamp - self.start_time))
sample = _WeightedSample(value, item_weight)
priority = item_weight / random()
if len(self.values) < self.size:
self.values[priority] = sample
else:
first_key = next(self.values.iterkeys())
if first_key < priority:
self.values.setdefault(priority, sample)
del self.values[first_key]
def get_snapshot(self):
return _WeightedSnapshot(self.values.values())
def test_iterkeys():
mapping = [(val, pos) for pos, val in enumerate(string.ascii_lowercase)]
temp = SortedDict(mapping)
assert list(temp.iterkeys()) == [key for key, pos in mapping]
def test_iterkeys():
mapping = [(val, pos) for pos, val in enumerate(string.ascii_lowercase)]
temp = SortedDict(mapping)
assert list(temp.iterkeys()) == [key for key, pos in mapping]
class DotMap(MutableMapping):
def __init__(self, *args, **kwargs):
self._map = SortedDict()
if args:
d = args[0]
if type(d) is dict:
for k, v in self.__call_items(d):
if type(v) is dict:
v = DotMap(v)
self._map[k] = v
if kwargs:
for k, v in self.__call_items(kwargs):
self._map[k] = v
@staticmethod
def __call_items(obj):
if hasattr(obj, 'iteritems') and ismethod(getattr(obj, 'iteritems')):
return obj.iteritems()
else:
return obj.items()
def items(self):
return self.iteritems()
def iteritems(self):
return self.__call_items(self._map)
def __iter__(self):
return self._map.__iter__()
def __setitem__(self, k, v):
self._map[k] = v
def __getitem__(self, k):
if k not in self._map:
# automatically extend to new DotMap
self[k] = DotMap()
return self._map[k]
def __setattr__(self, k, v):
if k == '_map':
super(DotMap, self).__setattr__(k, v)
else:
self[k] = v
def __getattr__(self, k):
if k == '_map':
return self._map
else:
return self[k]
def __delattr__(self, key):
return self._map.__delitem__(key)
def __contains__(self, k):
return self._map.__contains__(k)
def __str__(self):
items = []
for k, v in self.__call_items(self._map):
items.append('{0}={1}'.format(k, repr(v)))
out = 'DotMap({0})'.format(', '.join(items))
return out
def __repr__(self):
return str(self)
def to_dict(self):
d = {}
for k, v in self.items():
if type(v) is DotMap:
v = v.to_dict()
d[k] = v
return d
def pprint(self):
pprint(self.to_dict())
# proper dict subclassing
def values(self):
return self._map.values()
@staticmethod
def parse_other(other):
if type(other) is DotMap:
return other._map
else:
return other
def __cmp__(self, other):
other = DotMap.parse_other(other)
return self._map.__cmp__(other)
def __eq__(self, other):
other = DotMap.parse_other(other)
if not isinstance(other, dict):
return False
return self._map.__eq__(other)
def __ge__(self, other):
other = DotMap.parse_other(other)
return self._map.__ge__(other)
def __gt__(self, other):
other = DotMap.parse_other(other)
return self._map.__gt__(other)
def __le__(self, other):
other = DotMap.parseOther(other)
return self._map.__le__(other)
def __lt__(self, other):
other = DotMap.parse_other(other)
return self._map.__lt__(other)
def __ne__(self, other):
other = DotMap.parse_other(other)
return self._map.__ne__(other)
def __delitem__(self, key):
return self._map.__delitem__(key)
def __len__(self):
return self._map.__len__()
def copy(self):
return self
def get(self, key, default=None):
return self._map.get(key, default)
def has_key(self, key):
return key in self._map
def iterkeys(self):
return self._map.iterkeys()
def itervalues(self):
return self._map.itervalues()
def keys(self):
return self._map.keys()
def pop(self, key, default=None):
return self._map.pop(key, default)
def setdefault(self, key, default=None):
return self._map.setdefault(key, default)
def viewitems(self):
if version_info.major == 2 and version_info.minor >= 7:
return self._map.viewitems()
else:
return self._map.items()
def viewkeys(self):
if version_info.major == 2 and version_info.minor >= 7:
return self._map.viewkeys()
else:
return self._map.keys()
def viewvalues(self):
if version_info.major == 2 and version_info.minor >= 7:
return self._map.viewvalues()
else:
return self._map.values()
@classmethod
def fromkeys(cls, seq, value=None):
d = DotMap()
d._map = SortedDict.fromkeys(seq, value)
return d
