Use deque to consume generator

Author: barneygale

Lib/pathlib/__init__.py

@@ -11,6 +11,7 @@
 import os
 import posixpath
 import sys
+from collections import deque
 from errno import *
 from glob import _StringGlobber, _no_recurse_symlinks
 from itertools import chain
@@ -1092,8 +1093,7 @@ def copy(self, target, **kwargs):
         if not hasattr(target, 'with_segments'):
             target = self.with_segments(target)
         ensure_distinct_paths(self, target)
-        for _dst, _src in target._iter_copy_from(self, **kwargs):
-            pass
+        deque(target._iter_copy_from(self, **kwargs), maxlen=0)
         return target.joinpath()  # Empty join to ensure fresh metadata.
 
     def copy_into(self, target_dir, **kwargs):

Lib/pathlib/types.py

@@ -11,6 +11,7 @@
 
 
 from abc import ABC, abstractmethod
+from collections import deque
 from glob import _PathGlobber
 from io import text_encoding
 from pathlib._os import magic_open, ensure_distinct_paths, ensure_different_files, copyfileobj
@@ -337,8 +338,7 @@ def copy(self, target, **kwargs):
         Recursively copy this file or directory tree to the given destination.
         """
         ensure_distinct_paths(self, target)
-        for _dst, _src in target._iter_copy_from(self, **kwargs):
-            pass
+        deque(target._iter_copy_from(self, **kwargs), maxlen=0)
         return target.joinpath()  # Empty join to ensure fresh metadata.
 
     def copy_into(self, target_dir, **kwargs):