ENH: Add improved placeholder annotations for `np.lib`

1 files changed, 28 insertions, 0 deletions

diff --git a/numpy/lib/format.pyi b/numpy/lib/format.pyi
new file mode 100644
index 000000000..4c44d57bf
--- /dev/null
+++ b/numpy/lib/format.pyi
@@ -0,0 +1,28 @@
+import sys
+from typing import Any, List, Set
+
+if sys.version_info >= (3, 8):
+    from typing import Literal, Final
+else:
+    from typing_extensions import Literal, Final
+
+__all__: List[str]
+
+EXPECTED_KEYS: Final[Set[str]]
+MAGIC_PREFIX: Final[bytes]
+MAGIC_LEN: Literal[8]
+ARRAY_ALIGN: Literal[64]
+BUFFER_SIZE: Literal[262144]  # 2**18
+
+def magic(major, minor): ...
+def read_magic(fp): ...
+def dtype_to_descr(dtype): ...
+def descr_to_dtype(descr): ...
+def header_data_from_array_1_0(array): ...
+def write_array_header_1_0(fp, d): ...
+def write_array_header_2_0(fp, d): ...
+def read_array_header_1_0(fp): ...
+def read_array_header_2_0(fp): ...
+def write_array(fp, array, version=..., allow_pickle=..., pickle_kwargs=...): ...
+def read_array(fp, allow_pickle=..., pickle_kwargs=...): ...
+def open_memmap(filename, mode=..., dtype=..., shape=..., fortran_order=..., version=...): ...