mirror of https://github.com/python/cpython
Rework multiset methods to use less memory and to make fewer calls to __hash__.
This commit is contained in:
parent
c116da04a9
commit
efeb8bdaa2
|
@ -552,10 +552,13 @@ class Counter(dict):
|
|||
if not isinstance(other, Counter):
|
||||
return NotImplemented
|
||||
result = Counter()
|
||||
for elem in set(self) | set(other):
|
||||
newcount = self[elem] + other[elem]
|
||||
for elem, count in self.items():
|
||||
newcount = count + other[elem]
|
||||
if newcount > 0:
|
||||
result[elem] = newcount
|
||||
for elem, count in other.items():
|
||||
if elem not in self and count > 0:
|
||||
result[elem] = count
|
||||
return result
|
||||
|
||||
def __sub__(self, other):
|
||||
|
@ -568,10 +571,13 @@ class Counter(dict):
|
|||
if not isinstance(other, Counter):
|
||||
return NotImplemented
|
||||
result = Counter()
|
||||
for elem in set(self) | set(other):
|
||||
newcount = self[elem] - other[elem]
|
||||
for elem, count in self.items():
|
||||
newcount = count - other[elem]
|
||||
if newcount > 0:
|
||||
result[elem] = newcount
|
||||
for elem, count in other.items():
|
||||
if elem not in self and count < 0:
|
||||
result[elem] = 0 - count
|
||||
return result
|
||||
|
||||
def __or__(self, other):
|
||||
|
@ -584,11 +590,14 @@ class Counter(dict):
|
|||
if not isinstance(other, Counter):
|
||||
return NotImplemented
|
||||
result = Counter()
|
||||
for elem in set(self) | set(other):
|
||||
p, q = self[elem], other[elem]
|
||||
newcount = q if p < q else p
|
||||
for elem, count in self.items():
|
||||
other_count = other[elem]
|
||||
newcount = other_count if count < other_count else count
|
||||
if newcount > 0:
|
||||
result[elem] = newcount
|
||||
for elem, count in other.items():
|
||||
if elem not in self and count > 0:
|
||||
result[elem] = count
|
||||
return result
|
||||
|
||||
def __and__(self, other):
|
||||
|
@ -601,11 +610,9 @@ class Counter(dict):
|
|||
if not isinstance(other, Counter):
|
||||
return NotImplemented
|
||||
result = Counter()
|
||||
if len(self) < len(other):
|
||||
self, other = other, self
|
||||
for elem in _ifilter(self.__contains__, other):
|
||||
p, q = self[elem], other[elem]
|
||||
newcount = p if p < q else q
|
||||
for elem, count in self.items():
|
||||
other_count = other[elem]
|
||||
newcount = count if count < other_count else other_count
|
||||
if newcount > 0:
|
||||
result[elem] = newcount
|
||||
return result
|
||||
|
|
Loading…
Reference in New Issue