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Use lazy imports in collections #145054

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Merged
rhettinger merged 3 commits into from
Feb 21, 2026
+4 −10
Merged

Use lazy imports in collections #145054

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5554beb
No longer need to fake lazy imports
rhettinger Feb 20, 2026
6932490
Private name
rhettinger Feb 20, 2026
d4f406b
Switch to from-imports
rhettinger Feb 20, 2026
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14 changes: 4 additions & 10 deletions Lib/collections/__init__.py
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Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,8 @@
_sys.modules['collections.abc'] = _collections_abc
abc = _collections_abc

lazy from copy import copy as _copy
lazy from heapq import nlargest as _nlargest
from itertools import chain as _chain
from itertools import repeat as _repeat
from itertools import starmap as _starmap
Expand Down Expand Up @@ -59,8 +61,6 @@
except ImportError:
pass

heapq = None # Lazily imported


################################################################################
### OrderedDict
Expand Down Expand Up @@ -634,12 +634,7 @@ def most_common(self, n=None):
if n is None:
return sorted(self.items(), key=_itemgetter(1), reverse=True)

# Lazy import to speedup Python startup time
global heapq
if heapq is None:
import heapq

return heapq.nlargest(n, self.items(), key=_itemgetter(1))
return _nlargest(n, self.items(), key=_itemgetter(1))

def elements(self):
'''Iterator over elements repeating each as many times as its count.
Expand Down Expand Up @@ -1249,11 +1244,10 @@ def __copy__(self):
def copy(self):
if self.__class__ is UserDict:
return UserDict(self.data.copy())
import copy
data = self.data
try:
self.data = {}
c = copy.copy(self)
c = _copy(self)
finally:
self.data = data
c.update(self)
Expand Down
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