Suppress stop-iteration-return on itertools.cycle (#7766)

Co-authored-by: Pierre Sassoulas <pierre.sassoulas@gmail.com>
pylint-dev · Nov 17, 2022 · 9df5e8a · 9df5e8a
1 parent fa618cb
commit 9df5e8a
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Showing 4 changed files with 12 additions and 3 deletions.
diff --git a/doc/whatsnew/fragments/7765.false_positive b/doc/whatsnew/fragments/7765.false_positive
@@ -0,0 +1,3 @@
+Don't warn about ``stop-iteration-return`` when using ``next()`` over ``itertools.cycle``.
+
+Closes #7765
diff --git a/pylint/checkers/refactoring/refactoring_checker.py b/pylint/checkers/refactoring/refactoring_checker.py
@@ -35,7 +35,7 @@
     nodes.TryExcept, nodes.TryFinally, nodes.While, nodes.For, nodes.If
 ]
 
-KNOWN_INFINITE_ITERATORS = {"itertools.count"}
+KNOWN_INFINITE_ITERATORS = {"itertools.count", "itertools.cycle"}
 BUILTIN_EXIT_FUNCS = frozenset(("quit", "exit"))
 CALLS_THAT_COULD_BE_REPLACED_BY_WITH = frozenset(
     (

diff --git a/tests/functional/s/stop_iteration_inside_generator.py b/tests/functional/s/stop_iteration_inside_generator.py
@@ -110,14 +110,20 @@ def gen_next_with_sentinel():
     yield next([], 42)  # No bad return
 
 
-from itertools import count
+from itertools import count, cycle
 
 # https://github.com/PyCQA/pylint/issues/2158
 def generator_using_next():
     counter = count()
     number = next(counter)
     yield number * 2
 
+# https://github.com/PyCQA/pylint/issues/7765
+def infinite_iterator_itertools_cycle():
+    counter = cycle('ABCD')
+    val = next(counter)
+    yield val
+
 
 # pylint: disable=too-few-public-methods
 class SomeClassWithNext:

diff --git a/tests/functional/s/stop_iteration_inside_generator.txt b/tests/functional/s/stop_iteration_inside_generator.txt
@@ -4,4 +4,4 @@ stop-iteration-return:44:14:44:21:gen_next_raises_stopiter:Do not raise StopIter
 stop-iteration-return:66:18:66:25:gen_next_inside_wrong_try_except:Do not raise StopIteration in generator, use return statement instead:INFERENCE
 stop-iteration-return:80:12:80:31:gen_next_inside_wrong_try_except2:Do not raise StopIteration in generator, use return statement instead:INFERENCE
 stop-iteration-return:97:18:97:25:gen_dont_crash_on_no_exception:Do not raise StopIteration in generator, use return statement instead:INFERENCE
-stop-iteration-return:140:10:140:35:invalid_object_passed_to_next:Do not raise StopIteration in generator, use return statement instead:INFERENCE
+stop-iteration-return:146:10:146:35:invalid_object_passed_to_next:Do not raise StopIteration in generator, use return statement instead:INFERENCE