gh-136839: Refactor simple dict.update calls #136811

disconnect3d · 2025-07-19T12:58:31Z

This commit refactors simple dict.update({key: value}) calls which can be done via dict[key] = value instead.

I found those cases with the semgrep tool:

$ semgrep --lang python --pattern '$DICT.update({$A: ...})'

┌─────────────────┐
│ 5 Code Findings │
└─────────────────┘

    Lib/dataclasses.py
         1268┆ slots.update({slot: doc})

    Lib/multiprocessing/resource_tracker.py
           50┆ _CLEANUP_FUNCS.update({
           51┆     'semaphore': _multiprocessing.sem_unlink,
           52┆ })
            ⋮┆----------------------------------------
           53┆ _CLEANUP_FUNCS.update({
           54┆     'shared_memory': _posixshmem.shm_unlink,
           55┆ })

    Lib/tkinter/scrolledtext.py
           26┆ kw.update({'yscrollcommand': self.vbar.set})

    Lib/xmlrpc/server.py
          242┆ self.funcs.update({'system.multicall' : self.system_multicall})

Issue: minor cleanup: dict .update({x: y}) calls with a single item dict literal #136839

This commit refactors simple `dict.update({key: value})` calls which can be done via `dict[key] = value` instead. I found those cases with the [semgrep](https://semgrep.dev/) tool: ``` $ semgrep --lang python --pattern '$DICT.update({$A: ...})' ┌─────────────────┐ │ 5 Code Findings │ └─────────────────┘ Lib/dataclasses.py 1268┆ slots.update({slot: doc}) Lib/multiprocessing/resource_tracker.py 50┆ _CLEANUP_FUNCS.update({ 51┆ 'semaphore': _multiprocessing.sem_unlink, 52┆ }) ⋮┆---------------------------------------- 53┆ _CLEANUP_FUNCS.update({ 54┆ 'shared_memory': _posixshmem.shm_unlink, 55┆ }) Lib/tkinter/scrolledtext.py 26┆ kw.update({'yscrollcommand': self.vbar.set}) Lib/xmlrpc/server.py 242┆ self.funcs.update({'system.multicall' : self.system_multicall}) ```

disconnect3d · 2025-07-19T12:58:54Z

Lib/dataclasses.py

        if doc is not None:
            seen_docs = True
-        slots.update({slot: doc})
+        slots[slot] = doc


The slots is a dict here defined in line 1256

disconnect3d · 2025-07-19T12:59:14Z

Lib/multiprocessing/resource_tracker.py

-        'shared_memory': _posixshmem.shm_unlink,
-    })
+        _CLEANUP_FUNCS['semaphore'] = _multiprocessing.sem_unlink
+    _CLEANUP_FUNCS['shared_memory'] = _posixshmem.shm_unlink


_CLEANUP_FUNCS is a dict defined in line 35

disconnect3d · 2025-07-19T12:59:49Z

Lib/tkinter/scrolledtext.py

        self.vbar.pack(side=RIGHT, fill=Y)

-        kw.update({'yscrollcommand': self.vbar.set})
+        kw['yscrollcommand'] = self.vbar.set


The kw is a dict as passed to __init__(..., **kw) in line 21

disconnect3d · 2025-07-19T13:00:14Z

Lib/xmlrpc/server.py

        see http://www.xmlrpc.com/discuss/msgReader$1208"""

-        self.funcs.update({'system.multicall' : self.system_multicall})
+        self.funcs['system.multicall'] = self.system_multicall


self.funcs = {} is a dict as defined in line 167 of this file

gpshead · 2025-07-19T17:11:56Z

all of these are clearly correct. thanks.

miss-islington-app · 2025-07-19T17:12:13Z

Thanks @disconnect3d for the PR, and @gpshead for merging it 🌮🎉.. I'm working now to backport this PR to: 3.13, 3.14.
🐍🍒⛏🤖

Refactor simple dict.update calls This commit refactors simple `dict.update({key: value})` calls which can be done via `dict[key] = value` instead. I found those cases with the [semgrep](https://semgrep.dev/) tool: ``` $ semgrep --lang python --pattern '$DICT.update({$A: ...})' ┌─────────────────┐ │ 5 Code Findings │ └─────────────────┘ Lib/dataclasses.py 1268┆ slots.update({slot: doc}) Lib/multiprocessing/resource_tracker.py 50┆ _CLEANUP_FUNCS.update({ 51┆ 'semaphore': _multiprocessing.sem_unlink, 52┆ }) ⋮┆---------------------------------------- 53┆ _CLEANUP_FUNCS.update({ 54┆ 'shared_memory': _posixshmem.shm_unlink, 55┆ }) Lib/tkinter/scrolledtext.py 26┆ kw.update({'yscrollcommand': self.vbar.set}) Lib/xmlrpc/server.py 242┆ self.funcs.update({'system.multicall' : self.system_multicall}) ``` (cherry picked from commit 69ea1b3) Co-authored-by: Disconnect3d <[email protected]>

miss-islington-app · 2025-07-19T17:12:20Z

Sorry, @disconnect3d and @gpshead, I could not cleanly backport this to 3.13 due to a conflict.
Please backport using cherry_picker on command line.

cherry_picker 69ea1b3a8f45fec46add3272ad47f14ff5321ae8 3.13

bedevere-app · 2025-07-19T17:12:23Z

GH-136840 is a backport of this pull request to the 3.14 branch.

) gh-136839: Refactor simple dict.update calls (GH-136811) Refactor simple dict.update calls This commit refactors simple `dict.update({key: value})` calls which can be done via `dict[key] = value` instead. I found those cases with the [semgrep](https://semgrep.dev/) tool: ``` $ semgrep --lang python --pattern '$DICT.update({$A: ...})' ┌─────────────────┐ │ 5 Code Findings │ └─────────────────┘ Lib/dataclasses.py 1268┆ slots.update({slot: doc}) Lib/multiprocessing/resource_tracker.py 50┆ _CLEANUP_FUNCS.update({ 51┆ 'semaphore': _multiprocessing.sem_unlink, 52┆ }) ⋮┆---------------------------------------- 53┆ _CLEANUP_FUNCS.update({ 54┆ 'shared_memory': _posixshmem.shm_unlink, 55┆ }) Lib/tkinter/scrolledtext.py 26┆ kw.update({'yscrollcommand': self.vbar.set}) Lib/xmlrpc/server.py 242┆ self.funcs.update({'system.multicall' : self.system_multicall}) ``` (cherry picked from commit 69ea1b3) Co-authored-by: Disconnect3d <[email protected]>

Refactor simple dict.update calls This commit refactors simple `dict.update({key: value})` calls which can be done via `dict[key] = value` instead. I found those cases with the [semgrep](https://semgrep.dev/) tool: ``` $ semgrep --lang python --pattern '$DICT.update({$A: ...})' ┌─────────────────┐ │ 5 Code Findings │ └─────────────────┘ Lib/dataclasses.py 1268┆ slots.update({slot: doc}) Lib/multiprocessing/resource_tracker.py 50┆ _CLEANUP_FUNCS.update({ 51┆ 'semaphore': _multiprocessing.sem_unlink, 52┆ }) ⋮┆---------------------------------------- 53┆ _CLEANUP_FUNCS.update({ 54┆ 'shared_memory': _posixshmem.shm_unlink, 55┆ }) Lib/tkinter/scrolledtext.py 26┆ kw.update({'yscrollcommand': self.vbar.set}) Lib/xmlrpc/server.py 242┆ self.funcs.update({'system.multicall' : self.system_multicall}) ```

…36811) (python#136840) pythongh-136839: Refactor simple dict.update calls (pythonGH-136811) Refactor simple dict.update calls This commit refactors simple `dict.update({key: value})` calls which can be done via `dict[key] = value` instead. I found those cases with the [semgrep](https://semgrep.dev/) tool: ``` $ semgrep --lang python --pattern '$DICT.update({$A: ...})' ┌─────────────────┐ │ 5 Code Findings │ └─────────────────┘ Lib/dataclasses.py 1268┆ slots.update({slot: doc}) Lib/multiprocessing/resource_tracker.py 50┆ _CLEANUP_FUNCS.update({ 51┆ 'semaphore': _multiprocessing.sem_unlink, 52┆ }) ⋮┆---------------------------------------- 53┆ _CLEANUP_FUNCS.update({ 54┆ 'shared_memory': _posixshmem.shm_unlink, 55┆ }) Lib/tkinter/scrolledtext.py 26┆ kw.update({'yscrollcommand': self.vbar.set}) Lib/xmlrpc/server.py 242┆ self.funcs.update({'system.multicall' : self.system_multicall}) ``` (cherry picked from commit 69ea1b3) Co-authored-by: Disconnect3d <[email protected]>

disconnect3d requested review from ericvsmith and gpshead as code owners July 19, 2025 12:58

bedevere-app bot added the awaiting review label Jul 19, 2025

disconnect3d commented Jul 19, 2025

View reviewed changes

StanFromIreland added skip issue skip news type-refactor Code refactoring (with no changes in behavior) labels Jul 19, 2025

gpshead mentioned this pull request Jul 19, 2025

minor cleanup: dict .update({x: y}) calls with a single item dict literal #136839

Closed

gpshead changed the title ~~Refactor simple dict.update calls~~ gh-136839: Refactor simple dict.update calls Jul 19, 2025

gpshead self-assigned this Jul 19, 2025

gpshead added needs backport to 3.13 bugs and security fixes needs backport to 3.14 bugs and security fixes and removed skip issue labels Jul 19, 2025

gpshead merged commit 69ea1b3 into python:main Jul 19, 2025
54 checks passed

bedevere-app bot removed the awaiting review label Jul 19, 2025

bedevere-app bot removed the needs backport to 3.14 bugs and security fixes label Jul 19, 2025

gpshead removed the needs backport to 3.13 bugs and security fixes label Jul 19, 2025

AA-Turner added the sprint label Jul 19, 2025

disconnect3d deleted the refactor-simple-dict-update-calls branch July 20, 2025 09:18

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gh-136839: Refactor simple dict.update calls #136811

gh-136839: Refactor simple dict.update calls #136811

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