Utils lazy import (#386)

Co-authored-by: Korijn van Golen <[email protected]>

examples/compute_noop.py

@@ -5,7 +5,7 @@
 
 import wgpu
 import wgpu.backends.rs  # Select backend
-from wgpu.utils import compute_with_buffers  # Convenience function
+from wgpu.utils.compute import compute_with_buffers  # Convenience function
 
 
 # %% Shader and data

tests/test_api.py

@@ -123,24 +123,30 @@ def get_output_from_subprocess(code):
     return p.stdout.decode(errors="ignore")
 
 
-def test_do_not_import_utils_subpackage():
+def test_do_not_import_utils_submodules():
     # OK: use something from root package
     code = "import wgpu; print(wgpu.__version__)"
     out = get_output_from_subprocess(code)
     assert "Error" not in out
     assert wgpu.__version__ in out
 
-    # OK: use something from utils if we import it first
-    code = "import wgpu.utils; print(wgpu.utils.compute_with_buffers)"
+    # OK: wgpu.utils itself is always there
+    code = "import wgpu; print(wgpu.utils)"
     out = get_output_from_subprocess(code)
     assert "Error" not in out
-    assert "function compute_with_buffers" in out
+    assert "module 'wgpu.utils' from " in out
 
-    # FAIL: use something from utils if we only import wgpu
-    code = "import wgpu; print(wgpu.utils.compute_with_buffers)"
+    # OK: wgpu.utils itself is always there
+    code = "import wgpu; print(wgpu.utils.get_default_device)"
+    out = get_output_from_subprocess(code)
+    assert "Error" not in out
+    assert "function get_default_device" in out
+
+    # FAIL: use something from utils that's not imported
+    code = "import wgpu; print(wgpu.utils.compute.compute_with_buffers)"
     out = get_output_from_subprocess(code)
     assert "Error" in out
-    assert "has no attribute" in out and "utils" in out
+    assert "must be explicitly imported" in out and "utils" in out
 
     # Also, no numpy
     code = "import sys, wgpu.utils; print('numpy' in sys.modules)"

tests/test_util_compute.py

@@ -5,7 +5,7 @@
 import sys
 
 import wgpu.backends.rs  # noqa
-from wgpu.utils import compute_with_buffers
+from wgpu.utils.compute import compute_with_buffers
 
 from pytest import skip, mark, raises
 from testutils import run_tests, can_use_wgpu_lib, is_ci, iters_equal

wgpu/__init__.py

@@ -7,6 +7,8 @@
 from .enums import *  # noqa: F401,F403
 from .base import *  # noqa: F401,F403
 from .gui import WgpuCanvasInterface  # noqa: F401,F403
+from . import utils  # noqa: F401,F403
+
 
 __version__ = "0.11.0"
 version_info = tuple(map(int, __version__.split(".")))

wgpu/utils/__init__.py

@@ -1,5 +1,5 @@
 """
-Higher level utility functions. This module is not imported by default.
+Higher level utilities. Must be explicitly imported from ``wgpu.utils.xx``.
 """
 
 # The purpose of wgpu-py is to provide a Pythonic wrapper around
@@ -13,5 +13,30 @@
 # GPU/wgpu semantics), but without using low level details of the wgpu
 # API itself.
 
-from ._device import get_default_device  # noqa: F401
-from ._compute import compute_with_buffers  # noqa: F401
+# The get_default_device() is so small and generally convenient that we import it by default.
+from .device import get_default_device  # noqa: F401
+
+
+class _StubModule:
+    def __init__(self, module):
+        self._module = module
+        self.must_be_explicitly_imported = True
+
+    def __getattr__(self, *args, **kwargs):
+        raise RuntimeError(f"wgpu.utils.{self._module} must be explicitly imported.")
+
+    def __repr__(self):
+        return f"<Stub for wgpu.utils.{self._module} - {self._module} must be explicitly imported>"
+
+
+# Create stubs
+
+
+def compute_with_buffers(*args, **kwargs):
+    raise DeprecationWarning(
+        "wgpu.utils.compute_with_buffers() must now be imported from wgpu.utils.compute"
+    )
+
+
+compute = _StubModule("compute")
+shadertoy = _StubModule("shadertoy")