Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

Appearance settings

Commit cba55de

Browse filesBrowse files
committed
gh-113212: Document zero-arg super() inside nested functions and generator expressions
1 parent 3b7e6fd commit cba55de
Copy full SHA for cba55de

File tree

2 files changed

+25
-0
lines changed
Filter options

2 files changed

+25
-0
lines changed

‎Doc/library/functions.rst

Copy file name to clipboardExpand all lines: Doc/library/functions.rst
+23Lines changed: 23 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1845,6 +1845,29 @@ are always available. They are listed here in alphabetical order.
18451845
:func:`super`, see `guide to using super()
18461846
<https://rhettinger.wordpress.com/2011/05/26/super-considered-super/>`_.
18471847

1848+
.. note::
1849+
By default, if no second argument is provided, :func:`super` uses the first argument
1850+
of the immediately enclosing function definition, which is ``self`` under normal circumstances.
1851+
This may lead to unexpected behaviour if used inside nested functions or generator expressions
1852+
(the latter creates implicit nested functions). The following example will result in an exception::
1853+
1854+
class A:
1855+
def method(self):
1856+
return 1
1857+
1858+
class B(A):
1859+
def method(self):
1860+
return list(super().method() for _ in range(3)) # Expected [1, 1, 1] but TypeError will be raised.
1861+
1862+
In such cases, you should provide arguments explicitly::
1863+
1864+
class A:
1865+
def method(self):
1866+
return 1
1867+
1868+
class B(A):
1869+
def method(self):
1870+
return list(super(B, self).method() for _ in range(3)) # Will return [1, 1, 1].
18481871

18491872
.. _func-tuple:
18501873
.. class:: tuple()
+2Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,2 @@
1+
improve :py:class:`super` error message && document zero-arg :py:class:`super` inside nested
2+
functions and generator expressions

0 commit comments

Comments
0 (0)
Morty Proxy This is a proxified and sanitized view of the page, visit original site.