Don't emit ``*-not-iterating`` checks for builtins consumed by ``itertools``

Close #2731

3 files changed, 30 insertions, 8 deletions

diff --git a/ChangeLog b/ChangeLog
index 4d6080ff4..60de7a5d4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -7,6 +7,11 @@ What's New in Pylint 2.3.0?
 
 Release date: TBA
 
+
+* Don't emit ``*-not-iterating`` checks for builtins consumed by ``itertools``
+
+  Close #2731
+
 * Fix a crash caused by iterating over ``Uninferable`` in a string formatting check.
 
   Close #2727
diff --git a/pylint/checkers/python3.py b/pylint/checkers/python3.py
index 93be76844..c8e1dd92d 100644
--- a/pylint/checkers/python3.py
+++ b/pylint/checkers/python3.py
@@ -120,14 +120,14 @@ def _in_iterating_context(node):
         elif isinstance(parent.func, astroid.Attribute):
             if parent.func.attrname in ATTRIBUTES_ACCEPTS_ITERATOR:
                 return True
-            try:
-                inferred = next(parent.func.infer())
-            except astroid.InferenceError:
-                pass
-            else:
-                if inferred is not astroid.Uninferable:
-                    if inferred.qname() in _BUILTIN_METHOD_ACCEPTS_ITERATOR:
-                        return True
+
+        inferred = utils.safe_infer(parent.func)
+        if inferred:
+            if inferred.qname() in _BUILTIN_METHOD_ACCEPTS_ITERATOR:
+                return True
+            root = inferred.root()
+            if root and root.name == "itertools":
+                return True
     # If the call is in an unpacking, there's no need to warn,
     # since it can be considered iterating.
     elif isinstance(parent, astroid.Assign) and isinstance(
diff --git a/pylint/test/unittest_checker_python3.py b/pylint/test/unittest_checker_python3.py
index 623e35961..8354ed82e 100644
--- a/pylint/test/unittest_checker_python3.py
+++ b/pylint/test/unittest_checker_python3.py
@@ -177,6 +177,22 @@ class TestPython3Checker(testutils.CheckerTestCase):
         with self.assertNoMessages():
             self.walk(module)
 
+    def as_argument_to_itertools_functions(self, fxn):
+        code = """
+        from __future__ import absolute_import
+        import itertools
+        from itertools import product
+        for i,j in product({fxn}(), repeat=2):
+            pass
+        for i,j in itertools.product({fxn}(), repeat=2):
+            pass
+        """.format(
+            fxn=fxn
+        )
+        module = astroid.parse(code)
+        with self.assertNoMessages():
+            self.walk(module)
+
     def as_iterable_in_unpacking(self, fxn):
         node = astroid.extract_node(
             """
@@ -216,6 +232,7 @@ class TestPython3Checker(testutils.CheckerTestCase):
         self.as_argument_to_materialized_filter(fxn)
         self.as_iterable_in_yield_from(fxn)
         self.as_iterable_in_starred_context(fxn)
+        self.as_argument_to_itertools_functions(fxn)
 
         for func in (
             "iter",