Deprecated constants in favour of enums

Tests/test_file_apng.py

@@ -635,3 +635,13 @@ def test_apng_save_blend(tmp_path):
     with Image.open(test_file) as im:
         im.seek(2)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
+
+
+def test_constants_deprecation():
+    for enum, prefix in {
+        PngImagePlugin.Disposal: "APNG_DISPOSE_",
+        PngImagePlugin.Blend: "APNG_BLEND_",
+    }.items():
+        for name in enum.__members__:
+            with pytest.warns(DeprecationWarning):
+                assert getattr(PngImagePlugin, prefix + name) == enum[name]

Tests/test_file_blp.py

@@ -1,6 +1,6 @@
 import pytest
 
-from PIL import Image
+from PIL import BlpImagePlugin, Image
 
 from .helper import assert_image_equal_tofile
 
@@ -37,3 +37,14 @@ def test_crashes(test_file):
         with Image.open(f) as im:
             with pytest.raises(OSError):
                 im.load()
+
+
+def test_constants_deprecation():
+    for enum, prefix in {
+        BlpImagePlugin.Format: "BLP_FORMAT_",
+        BlpImagePlugin.Encoding: "BLP_ENCODING_",
+        BlpImagePlugin.AlphaEncoding: "BLP_ALPHA_ENCODING_",
+    }.items():
+        for name in enum.__members__:
+            with pytest.warns(DeprecationWarning):
+                assert getattr(BlpImagePlugin, prefix + name) == enum[name]

Tests/test_file_ftex.py

@@ -1,4 +1,6 @@
-from PIL import Image
+import pytest
+
+from PIL import FtexImagePlugin, Image
 
 from .helper import assert_image_equal_tofile, assert_image_similar
 
@@ -12,3 +14,12 @@ def test_load_dxt1():
     with Image.open("Tests/images/ftex_dxt1.ftc") as im:
         with Image.open("Tests/images/ftex_dxt1.png") as target:
             assert_image_similar(im, target.convert("RGBA"), 15)
+
+
+def test_constants_deprecation():
+    for enum, prefix in {
+        FtexImagePlugin.Format: "FORMAT_",
+    }.items():
+        for name in enum.__members__:
+            with pytest.warns(DeprecationWarning):
+                assert getattr(FtexImagePlugin, prefix + name) == enum[name]

Tests/test_image.py

@@ -802,6 +802,31 @@ class TestImage:
         with pytest.warns(DeprecationWarning):
             assert Image.CONTAINER == 2
 
+    def test_constants_deprecation(self):
+        with pytest.warns(DeprecationWarning):
+            assert Image.NEAREST == 0
+        with pytest.warns(DeprecationWarning):
+            assert Image.NONE == 0
+
+        with pytest.warns(DeprecationWarning):
+            assert Image.LINEAR == Image.Resampling.BILINEAR
+        with pytest.warns(DeprecationWarning):
+            assert Image.CUBIC == Image.Resampling.BICUBIC
+        with pytest.warns(DeprecationWarning):
+            assert Image.ANTIALIAS == Image.Resampling.LANCZOS
+
+        for enum in (
+            Image.Transpose,
+            Image.Transform,
+            Image.Resampling,
+            Image.Dither,
+            Image.Palette,
+            Image.Quantize,
+        ):
+            for name in enum.__members__:
+                with pytest.warns(DeprecationWarning):
+                    assert getattr(Image, name) == enum[name]
+
     @pytest.mark.parametrize(
         "path",
         [

Tests/test_imagecms.py

@@ -593,3 +593,13 @@ def test_auxiliary_channels_isolated():
                 )
 
                 assert_image_equal(test_image.convert(dst_format[2]), reference_image)
+
+
+def test_constants_deprecation():
+    for enum, prefix in {
+        ImageCms.Intent: "INTENT_",
+        ImageCms.Direction: "DIRECTION_",
+    }.items():
+        for name in enum.__members__:
+            with pytest.warns(DeprecationWarning):
+                assert getattr(ImageCms, prefix + name) == enum[name]

Tests/test_imagefont.py

@@ -1022,3 +1022,12 @@ def test_oom(test_file):
         font = ImageFont.truetype(BytesIO(f.read()))
         with pytest.raises(Image.DecompressionBombError):
             font.getmask("Test Text")
+
+
+def test_constants_deprecation():
+    for enum, prefix in {
+        ImageFont.Layout: "LAYOUT_",
+    }.items():
+        for name in enum.__members__:
+            with pytest.warns(DeprecationWarning):
+                assert getattr(ImageFont, prefix + name) == enum[name]

src/PIL/BlpImagePlugin.py

@@ -30,6 +30,7 @@ BLP files come in many different flavours:
 """
 
 import struct
+import warnings
 from enum import IntEnum
 from io import BytesIO
 
@@ -52,11 +53,31 @@ class AlphaEncoding(IntEnum):
     DXT5 = 7
 
 
-globals().update({"BLP_FORMAT_" + k: v for k, v in Format.__members__.items()})
-globals().update({"BLP_ENCODING_" + k: v for k, v in Encoding.__members__.items()})
-globals().update(
-    {"BLP_ALPHA_ENCODING_" + k: v for k, v in AlphaEncoding.__members__.items()}
-)
+def __getattr__(name):
+    deprecated = "deprecated and will be removed in Pillow 10 (2023-07-01). "
+    for enum, prefix in {
+        Format: "BLP_FORMAT_",
+        Encoding: "BLP_ENCODING_",
+        AlphaEncoding: "BLP_ALPHA_ENCODING_",
+    }.items():
+        if name.startswith(prefix):
+            name = name[len(prefix) :]
+            if name in enum.__members__:
+                warnings.warn(
+                    prefix
+                    + name
+                    + " is "
+                    + deprecated
+                    + "Use "
+                    + enum.__name__
+                    + "."
+                    + name
+                    + " instead.",
+                    DeprecationWarning,
+                    stacklevel=2,
+                )
+                return enum[name]
+    raise AttributeError(f"module '{__name__}' has no attribute '{name}'")
 
 
 def unpack_565(i):

src/PIL/FtexImagePlugin.py

@@ -52,6 +52,7 @@ Note: All data is stored in little-Endian (Intel) byte order.
 """
 
 import struct
+import warnings
 from enum import IntEnum
 from io import BytesIO
 
@@ -65,7 +66,27 @@ class Format(IntEnum):
     UNCOMPRESSED = 1
 
 
-globals().update({"FORMAT_" + k: v for k, v in Format.__members__.items()})
+def __getattr__(name):
+    deprecated = "deprecated and will be removed in Pillow 10 (2023-07-01). "
+    for enum, prefix in {Format: "FORMAT_"}.items():
+        if name.startswith(prefix):
+            name = name[len(prefix) :]
+            if name in enum.__members__:
+                warnings.warn(
+                    prefix
+                    + name
+                    + " is "
+                    + deprecated
+                    + "Use "
+                    + enum.__name__
+                    + "."
+                    + name
+                    + " instead.",
+                    DeprecationWarning,
+                    stacklevel=2,
+                )
+                return enum[name]
+    raise AttributeError(f"module '{__name__}' has no attribute '{name}'")
 
 
 class FtexImageFile(ImageFile.ImageFile):

src/PIL/Image.py

@@ -54,15 +54,57 @@ from ._util import deferred_error, isPath
 
 
 def __getattr__(name):
+    deprecated = "deprecated and will be removed in Pillow 10 (2023-07-01). "
     categories = {"NORMAL": 0, "SEQUENCE": 1, "CONTAINER": 2}
     if name in categories:
         warnings.warn(
-            "Image categories are deprecated and will be removed in Pillow 10 "
-            "(2023-07-01). Use is_animated instead.",
+            "Image categories are " + deprecated + "Use is_animated instead.",
             DeprecationWarning,
             stacklevel=2,
         )
         return categories[name]
+    elif name in ("NEAREST", "NONE"):
+        warnings.warn(
+            name
+            + " is "
+            + deprecated
+            + "Use Resampling.NEAREST or Dither.NONE instead.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return 0
+    old_resampling = {
+        "LINEAR": "BILINEAR",
+        "CUBIC": "BICUBIC",
+        "ANTIALIAS": "LANCZOS",
+    }
+    if name in old_resampling:
+        warnings.warn(
+            name
+            + " is "
+            + deprecated
+            + "Use Resampling."
+            + old_resampling[name]
+            + " instead.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return Resampling[old_resampling[name]]
+    for enum in (Transpose, Transform, Resampling, Dither, Palette, Quantize):
+        if name in enum.__members__:
+            warnings.warn(
+                name
+                + " is "
+                + deprecated
+                + "Use "
+                + enum.__name__
+                + "."
+                + name
+                + " instead.",
+                DeprecationWarning,
+                stacklevel=2,
+            )
+            return enum[name]
     raise AttributeError(f"module '{__name__}' has no attribute '{name}'")
 
 
@@ -199,10 +241,6 @@ class Quantize(IntEnum):
     LIBIMAGEQUANT = 3
 
 
-for enum in (Transpose, Transform, Resampling, Dither, Palette, Quantize):
-    globals().update(enum.__members__)
-NEAREST = NONE = 0
-
 if hasattr(core, "DEFAULT_STRATEGY"):
     DEFAULT_STRATEGY = core.DEFAULT_STRATEGY
     FILTERED = core.FILTERED

src/PIL/ImageCms.py

@@ -16,6 +16,7 @@
 # below for the original description.
 
 import sys
+import warnings
 from enum import IntEnum
 
 from PIL import Image
@@ -115,8 +116,28 @@ class Direction(IntEnum):
     PROOF = 2
 
 
-globals().update({"INTENT_" + k: v for k, v in Intent.__members__.items()})
-globals().update({"DIRECTION_" + k: v for k, v in Direction.__members__.items()})
+def __getattr__(name):
+    deprecated = "deprecated and will be removed in Pillow 10 (2023-07-01). "
+    for enum, prefix in {Intent: "INTENT_", Direction: "DIRECTION_"}.items():
+        if name.startswith(prefix):
+            name = name[len(prefix) :]
+            if name in enum.__members__:
+                warnings.warn(
+                    prefix
+                    + name
+                    + " is "
+                    + deprecated
+                    + "Use "
+                    + enum.__name__
+                    + "."
+                    + name
+                    + " instead.",
+                    DeprecationWarning,
+                    stacklevel=2,
+                )
+                return enum[name]
+    raise AttributeError(f"module '{__name__}' has no attribute '{name}'")
+
 
 #
 # flags

src/PIL/ImageFont.py

@@ -28,6 +28,7 @@
 import base64
 import os
 import sys
+import warnings
 from enum import IntEnum
 from io import BytesIO
 
@@ -40,7 +41,27 @@ class Layout(IntEnum):
     RAQM = 1
 
 
-globals().update({"LAYOUT_" + k: v for k, v in Layout.__members__.items()})
+def __getattr__(name):
+    deprecated = "deprecated and will be removed in Pillow 10 (2023-07-01). "
+    for enum, prefix in {Layout: "LAYOUT_"}.items():
+        if name.startswith(prefix):
+            name = name[len(prefix) :]
+            if name in enum.__members__:
+                warnings.warn(
+                    prefix
+                    + name
+                    + " is "
+                    + deprecated
+                    + "Use "
+                    + enum.__name__
+                    + "."
+                    + name
+                    + " instead.",
+                    DeprecationWarning,
+                    stacklevel=2,
+                )
+                return enum[name]
+    raise AttributeError(f"module '{__name__}' has no attribute '{name}'")
 
 
 class _imagingft_not_installed:

src/PIL/PngImagePlugin.py

@@ -130,8 +130,27 @@ class Blend(IntEnum):
     """
 
 
-globals().update({"APNG_DISPOSE_" + k: v for k, v in Disposal.__members__.items()})
-globals().update(Blend.__members__)
+def __getattr__(name):
+    deprecated = "deprecated and will be removed in Pillow 10 (2023-07-01). "
+    for enum, prefix in {Disposal: "APNG_DISPOSE_", Blend: "APNG_BLEND_"}.items():
+        if name.startswith(prefix):
+            name = name[len(prefix) :]
+            if name in enum.__members__:
+                warnings.warn(
+                    prefix
+                    + name
+                    + " is "
+                    + deprecated
+                    + "Use "
+                    + enum.__name__
+                    + "."
+                    + name
+                    + " instead.",
+                    DeprecationWarning,
+                    stacklevel=2,
+                )
+                return enum[name]
+    raise AttributeError(f"module '{__name__}' has no attribute '{name}'")
 
 
 def _safe_zlib_decompress(s):