manual-from-import.md

manual-from-import (PLR0402)

target-version = "py315"

[lint]
select = ["PLR0402"]

Both modules listed

When __lazy_modules__ contains both the package and its submodule, the fix preserves laziness.

__lazy_modules__ = ["foo", "foo.bar"]
import foo.bar as bar  # snapshot: manual-from-import

error[PLR0402]: Use `from foo import bar` in lieu of alias
 --> src/mdtest_snippet.py:2:8
  |
2 | import foo.bar as bar  # snapshot: manual-from-import
  |        ^^^^^^^^^^^^^^
help: Replace with `from foo import bar`
  |
1 | __lazy_modules__ = ["foo", "foo.bar"]
  - import foo.bar as bar  # snapshot: manual-from-import
2 + from foo import bar  # snapshot: manual-from-import
  |

Only the submodule listed

A from import checks its containing module for membership in __lazy_modules__. Rewriting this import would make it eager, so the diagnostic has no fix.

__lazy_modules__ = ["foo.bar"]
import foo.bar as bar  # snapshot: manual-from-import

error[PLR0402]: Use `from foo import bar` in lieu of alias
 --> src/mdtest_snippet.py:2:8
  |
2 | import foo.bar as bar  # snapshot: manual-from-import
  |        ^^^^^^^^^^^^^^
help: Replace with `from foo import bar`

Only the package listed

Listing a package does not make imports of its submodules lazy. Rewriting this import would make it lazy, so the diagnostic has no fix.

__lazy_modules__ = ["foo"]
import foo.bar as bar  # snapshot: manual-from-import

error[PLR0402]: Use `from foo import bar` in lieu of alias
 --> src/mdtest_snippet.py:2:8
  |
2 | import foo.bar as bar  # snapshot: manual-from-import
  |        ^^^^^^^^^^^^^^
help: Replace with `from foo import bar`

Explicit lazy imports

The fix preserves the lazy keyword, so the import remains lazy even when the package is absent from __lazy_modules__.

__lazy_modules__ = ["foo.bar"]
lazy import foo.bar as bar  # snapshot: manual-from-import

error[PLR0402]: Use `from foo import bar` in lieu of alias
 --> src/mdtest_snippet.py:2:13
  |
2 | lazy import foo.bar as bar  # snapshot: manual-from-import
  |             ^^^^^^^^^^^^^^
help: Replace with `from foo import bar`
  |
1 | __lazy_modules__ = ["foo.bar"]
  - lazy import foo.bar as bar  # snapshot: manual-from-import
2 + lazy from foo import bar  # snapshot: manual-from-import
  |

Unknown declarations

When the declaration's contents are unknown, the rule cannot establish whether the fix preserves laziness, so no fix is offered.

__lazy_modules__ = configured_lazy_modules
import foo.bar as bar  # snapshot: manual-from-import

error[PLR0402]: Use `from foo import bar` in lieu of alias
 --> src/mdtest_snippet.py:2:8
  |
2 | import foo.bar as bar  # snapshot: manual-from-import
  |        ^^^^^^^^^^^^^^
help: Replace with `from foo import bar`

Imports inside functions

Imports inside functions are eager regardless of __lazy_modules__, so an unknown declaration does not prevent a fix.

__lazy_modules__ = configured_lazy_modules


def import_in_function():
    import foo.bar as bar  # snapshot: manual-from-import

error[PLR0402]: Use `from foo import bar` in lieu of alias
 --> src/mdtest_snippet.py:5:12
  |
5 |     import foo.bar as bar  # snapshot: manual-from-import
  |            ^^^^^^^^^^^^^^
help: Replace with `from foo import bar`
  |
4 | def import_in_function():
  -     import foo.bar as bar  # snapshot: manual-from-import
5 +     from foo import bar  # snapshot: manual-from-import
  |