ENH: add type stubs from numpy-stubs

Add the type stubs and tests from numpy-stubs. Things this entails:

- Copy over the stubs (numpy/__init__.pyi and
  numpy/core/_internal.pyi)
  - The only modification made was removing `ndarray.tostring` since
    it is deprecated
- Update some setup.py files to include pyi files
- Move the tests from numpy-stubs/tests into numpy/tests
  - Skip them if mypy is not installed (planning on setting up CI in a
    future PR)
  - Add a mypy.ini; use it to configure mypy in the tests
    - It tells mypy where to find NumPy in the test env
    - It ignores internal NumPy type errors (since we only want to
      consider errors from the tests cases)
  - Some small edits were made to fix test cases that were emitting
    deprecation warnings
 - Add numpy/py.typed so that the types are picked up in an
   installed version of NumPy

1 files changed, 30 insertions, 0 deletions

diff --git a/numpy/tests/reveal/scalars.py b/numpy/tests/reveal/scalars.py
new file mode 100644
index 000000000..8a9555fc3
--- /dev/null
+++ b/numpy/tests/reveal/scalars.py
@@ -0,0 +1,30 @@
+import numpy as np
+
+x = np.complex64(3 + 2j)
+
+reveal_type(x.real)  # E: numpy.float32
+reveal_type(x.imag)  # E: numpy.float32
+
+reveal_type(x.real.real)  # E: numpy.float32
+reveal_type(x.real.imag)  # E: numpy.float32
+
+reveal_type(x.itemsize)  # E: int
+reveal_type(x.shape)  # E: tuple[builtins.int]
+reveal_type(x.strides)  # E: tuple[builtins.int]
+
+# Time structures
+dt = np.datetime64(0, "D")
+td = np.timedelta64(0, "D")
+
+reveal_type(dt + td)  # E: numpy.datetime64
+reveal_type(dt + 1)  # E: numpy.datetime64
+reveal_type(dt - dt)  # E: numpy.timedelta64
+reveal_type(dt - 1)  # E: numpy.timedelta64
+
+reveal_type(td + td)  # E: numpy.timedelta64
+reveal_type(td + 1)  # E: numpy.timedelta64
+reveal_type(td - td)  # E: numpy.timedelta64
+reveal_type(td - 1)  # E: numpy.timedelta64
+reveal_type(td / 1.0)  # E: numpy.timedelta64
+reveal_type(td / td)  # E: float
+reveal_type(td % td)  # E: numpy.timedelta64