fix: remove deprecated dj.key_hash and dj.Di

- Remove key_hash function (legacy job table debugging)
- Remove hash.py module
- Fix test_erd.py to use dj.Diagram instead of dj.Di
- Bump version to 2.0.0a20

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: dimitri-yatsenko

src/datajoint/__init__.py

@@ -54,7 +54,6 @@
     "errors",
     "migrate",
     "DataJointError",
-    "key_hash",
     "logger",
     "cli",
     "ValidationResult",
@@ -78,7 +77,6 @@
 from .connection import Connection, conn
 from .errors import DataJointError
 from .expression import AndList, Not, Top, U
-from .hash import key_hash
 from .logging import logger
 from .objectref import ObjectRef
 from .schemas import Schema, VirtualModule, list_schemas, virtual_schema

src/datajoint/hash.py

@@ -1,4 +1,4 @@
 # version bump auto managed by Github Actions:
 # label_prs.yaml(prep), release.yaml(bump), post_release.yaml(edit)
 # manually set this version will be eventually overwritten by the above actions
-__version__ = "2.0.0a19"
+__version__ = "2.0.0a20"

src/datajoint/version.py

@@ -32,7 +32,7 @@ def test_erd(schema_simp):
 def test_erd_algebra(schema_simp):
     erd0 = dj.ERD(B)
     erd1 = erd0 + 3
-    erd2 = dj.Di(E) - 3
+    erd2 = dj.Diagram(E) - 3
     erd3 = erd1 * erd2
     erd4 = (erd0 + E).add_parts() - B - E
     assert erd0.nodes_to_show == set(cls.full_table_name for cls in [B])
@@ -56,7 +56,7 @@ def test_make_image(schema_simp):
 
 def test_part_table_parsing(schema_simp):
     # https://github.com/datajoint/datajoint-python/issues/882
-    erd = dj.Di(schema_simp, context=LOCALS_SIMPLE)
+    erd = dj.Diagram(schema_simp, context=LOCALS_SIMPLE)
     graph = erd._make_graph()
     assert "OutfitLaunch" in graph.nodes()
     assert "OutfitLaunch.OutfitPiece" in graph.nodes()