Thanks to visit codestin.com
Credit goes to github.com

Skip to content

Make --allow-redefinition mean --allow-redefinition-new #21276

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
JukkaL merged 13 commits into from
Apr 22, 2026
Merged

Make --allow-redefinition mean --allow-redefinition-new #21276

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
13 commits
Select commit Hold shift + click to select a range
0590497
Rename allow_redefinitio_new -> allow_redefinition
JukkaL Apr 20, 2026
1c4a3ff
Update more
JukkaL Apr 20, 2026
5838f6b
Update tests
JukkaL Apr 20, 2026
83fc2a4
Test fixes
JukkaL Apr 20, 2026
116866d
Lint
JukkaL Apr 20, 2026
b79d8ec
Doc updates
JukkaL Apr 20, 2026
ad77e94
Minor docs update
JukkaL Apr 20, 2026
f1e6d7d
Update tests
JukkaL Apr 20, 2026
1a2b60d
Address code review
JukkaL Apr 21, 2026
56327fb
Merge branch 'master' into allow-redef-rename
JukkaL Apr 22, 2026
d4f6a85
Update tests
JukkaL Apr 22, 2026
c8e6416
Update test case to use legacy --allow-redefinition-new alias
JukkaL Apr 22, 2026
a5aecfd
Fix after merge
JukkaL Apr 22, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Prev Previous commit
Next Next commit
Doc updates
  • Loading branch information
@JukkaL
JukkaL committed Apr 20, 2026
commit b79d8ecd4da5b57c0c53fc9fa5f0ff7e5d47f626
17 changes: 7 additions & 10 deletions docs/source/command_line.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -595,7 +595,7 @@ of the above sections.
This flag causes mypy to suppress errors caused by not being able to fully
infer the types of global and class variables.

.. option:: --allow-redefinition-new
.. option:: --allow-redefinition

By default, mypy won't allow a variable to be redefined with an
unrelated type. This flag enables the redefinition of *unannotated*
Expand All @@ -613,7 +613,7 @@ of the above sections.
# Type of "x" is "int | str" here.
return x

Without the new flag, mypy only supports inferring optional types
Without this flag, mypy only supports inferring optional types
(``X | None``) from multiple assignments. With this option enabled,
mypy can infer arbitrary union types.

Expand Down Expand Up @@ -646,23 +646,20 @@ of the above sections.
Note: We are planning to turn this flag on by default in a future mypy
release.

.. option:: --allow-redefinition
.. option:: --allow-redefinition-new

This is an alias to :option:`--allow-redefinition-old <mypy --allow-redefinition-old>`.
In mypy v2.0 this will point to
:option:`--allow-redefinition-new <mypy --allow-redefinition-new>`, and will
eventually became the default.
Deprecated alias for :option:`--allow-redefinition <mypy --allow-redefinition>`.

.. option:: --allow-redefinition-old

This is an older variant of
:option:`--allow-redefinition-new <mypy --allow-redefinition-new>`.
This is an older, more limited variant of
:option:`--allow-redefinition <mypy --allow-redefinition>`.
This flag enables redefinition of a variable with an
arbitrary type *in some contexts*: only redefinitions within the
same block and nesting depth as the original definition are allowed.

We have no plans to remove this flag, but we expect that
:option:`--allow-redefinition-new <mypy --allow-redefinition-new>`
:option:`--allow-redefinition <mypy --allow-redefinition>`
will replace this flag for new use cases eventually.

Example where this can be useful:
Expand Down
17 changes: 8 additions & 9 deletions docs/source/config_file.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -713,7 +713,7 @@ section of the command line docs.
Causes mypy to suppress errors caused by not being able to fully
infer the types of global and class variables.

.. confval:: allow_redefinition_new
.. confval:: allow_redefinition

:type: boolean
:default: False
Expand Down Expand Up @@ -763,6 +763,13 @@ section of the command line docs.
Note: We are planning to turn this flag on by default in a future mypy
release.

.. confval:: allow_redefinition_new

:type: boolean
:default: False

Deprecated alias for :confval:`allow_redefinition`.

.. confval:: allow_redefinition_old

:type: boolean
Expand All @@ -789,14 +796,6 @@ section of the command line docs.
items = "100" # valid, items now has type str
items = int(items) # valid, items now has type int

.. confval:: allow_redefinition

:type: boolean
:default: False

An alias to :confval:`allow_redefinition_old`, in mypy v2.0 this will point to
:confval:`allow_redefinition_new`, and will eventually became the default.

.. confval:: local_partial_types

:type: boolean
Expand Down