Issue #18518: timeit now rejects statements which can't be compiled outside
a function or a loop (e.g. "return" or "break").
diff --git a/Doc/library/timeit.rst b/Doc/library/timeit.rst
index 19b5e4e..503a705 100644
--- a/Doc/library/timeit.rst
+++ b/Doc/library/timeit.rst
@@ -64,12 +64,6 @@
Create a :class:`Timer` instance with the given statement, *setup* code and
*timer* function and run its :meth:`.timeit` method with *number* executions.
- .. note::
-
- Because :meth:`.timeit` is executing *stmt*, placing a return statement
- in *stmt* will prevent :meth:`.timeit` from returning execution time.
- It will instead return the data specified by your return statement.
-
.. function:: repeat(stmt='pass', setup='pass', timer=<default timer>, repeat=3, number=1000000)
diff --git a/Lib/test/test_timeit.py b/Lib/test/test_timeit.py
index 625fb8d..09e76e0 100644
--- a/Lib/test/test_timeit.py
+++ b/Lib/test/test_timeit.py
@@ -73,9 +73,21 @@
def test_timer_invalid_stmt(self):
self.assertRaises(ValueError, timeit.Timer, stmt=None)
+ self.assertRaises(SyntaxError, timeit.Timer, stmt='return')
+ self.assertRaises(SyntaxError, timeit.Timer, stmt='yield')
+ self.assertRaises(SyntaxError, timeit.Timer, stmt='yield from ()')
+ self.assertRaises(SyntaxError, timeit.Timer, stmt='break')
+ self.assertRaises(SyntaxError, timeit.Timer, stmt='continue')
+ self.assertRaises(SyntaxError, timeit.Timer, stmt='from timeit import *')
def test_timer_invalid_setup(self):
self.assertRaises(ValueError, timeit.Timer, setup=None)
+ self.assertRaises(SyntaxError, timeit.Timer, setup='return')
+ self.assertRaises(SyntaxError, timeit.Timer, setup='yield')
+ self.assertRaises(SyntaxError, timeit.Timer, setup='yield from ()')
+ self.assertRaises(SyntaxError, timeit.Timer, setup='break')
+ self.assertRaises(SyntaxError, timeit.Timer, setup='continue')
+ self.assertRaises(SyntaxError, timeit.Timer, setup='from timeit import *')
fake_setup = "import timeit; timeit._fake_timer.setup()"
fake_stmt = "import timeit; timeit._fake_timer.inc()"
diff --git a/Lib/timeit.py b/Lib/timeit.py
index ead2030..9cec000 100755
--- a/Lib/timeit.py
+++ b/Lib/timeit.py
@@ -109,6 +109,12 @@
self.timer = timer
ns = {}
if isinstance(stmt, str):
+ # Check that the code can be compiled outside a function
+ if isinstance(setup, str):
+ compile(setup, dummy_src_name, "exec")
+ compile(setup + '\n' + stmt, dummy_src_name, "exec")
+ else:
+ compile(stmt, dummy_src_name, "exec")
stmt = reindent(stmt, 8)
if isinstance(setup, str):
setup = reindent(setup, 4)
diff --git a/Misc/NEWS b/Misc/NEWS
index c30c9d5..198092c 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -50,6 +50,9 @@
Library
-------
+- Issue #18518: timeit now rejects statements which can't be compiled outside
+ a function or a loop (e.g. "return" or "break").
+
- Issue #23094: Fixed readline with frames in Python implementation of pickle.
- Issue #23268: Fixed bugs in the comparison of ipaddress classes.