add delete where command

chroma_functions.py

@@ -44,6 +44,13 @@ def delete_collection(name: str) -> None:
     client.delete_collection(name=name)
 
 
+def delete_data(collection_name: str, where: dict[str, str]) -> int:
+    _, collection = _get_client_and_collection(collection_name)
+    result = collection.delete(where=where)
+
+    return int(result.get("deleted", 0))
+
+
 def count_collection(collection_name: str) -> int:
     _, collection = _get_client_and_collection(collection_name)
 

cli_app.py

@@ -9,7 +9,10 @@ from chromadb.errors import InternalError, NotFoundError
 from handlers.add_data import handle_add_data
 from handlers.count_collection import handle_count_collection
 from handlers.create_collection import handle_create_collection
-from handlers.delete_collection import handle_delete_collection
+from handlers.delete_collection import (
+    handle_delete_collection,
+    handle_delete_records,
+)
 from handlers.list_collections import handle_list_collections
 from handlers.query import handle_query
 
@@ -81,11 +84,25 @@ COMMANDS: dict[str, CommandConfig] = {
             ),
         ),
     ),
+    "delete": CommandConfig(
+        handler=handle_delete_records,
+        error_handlers=(
+            CliErrorHandler(
+                exception_type=NotFoundError,
+                message=lambda args: f"Collection '{args.collection}' does not exist.",
+            ),
+            CliErrorHandler(
+                exception_type=ValueError,
+                message=lambda args: str(args.error_message),
+            ),
+        ),
+    ),
 }
 
 
 def execute_command(args: Namespace) -> int:
     command = COMMANDS[args.command]
+    args.error_message = "An unexpected value was provided."
 
     try:
         return command.handler(args)

cli_parser.py

@@ -8,6 +8,8 @@ from dataclasses import dataclass
 class ArgumentSpec:
     name: str
     help: str
+    required: bool = False
+    metavar: str | None = None
 
 
 @dataclass(frozen=True, slots=True)
@@ -62,6 +64,20 @@ COMMAND_SPECS: tuple[CommandSpec, ...] = (
             ArgumentSpec("query_text", "The text to query."),
         ),
     ),
+    CommandSpec(
+        name="delete",
+        aliases=("del",),
+        help="Delete records from a collection using a metadata filter.",
+        arguments=(
+            ArgumentSpec("collection", "Name of the target collection."),
+            ArgumentSpec(
+                "--where",
+                "Metadata filter in the format <condition>=<value>.",
+                required=True,
+                metavar="CONDITION=VALUE",
+            ),
+        ),
+    ),
 )
 
 
@@ -77,7 +93,15 @@ def _add_command(
     )
 
     for argument in command.arguments:
-        subparser.add_argument(argument.name, help=argument.help)
+        argument_kwargs: dict[str, object] = {"help": argument.help}
+
+        if argument.metavar is not None:
+            argument_kwargs["metavar"] = argument.metavar
+
+        if argument.name.startswith("-"):
+            argument_kwargs["required"] = argument.required
+
+        subparser.add_argument(argument.name, **argument_kwargs)
 
     subparser.set_defaults(command=command.name)
 

handlers/delete_collection.py

@@ -1,9 +1,40 @@
 from argparse import Namespace
 
-from chroma_functions import delete_collection
+from chroma_functions import delete_collection, delete_data
+
+
+def _parse_where_clause(where_clause: str) -> dict[str, str]:
+    condition, separator, value = where_clause.partition("=")
+
+    if separator == "":
+        raise ValueError("Invalid --where value. Expected <condition>=<value>.")
+
+    condition = condition.strip()
+    value = value.strip()
+
+    if not condition or not value:
+        raise ValueError("Invalid --where value. Expected <condition>=<value>.")
+
+    return {condition: value}
 
 
 def handle_delete_collection(args: Namespace) -> int:
     delete_collection(args.collection)
     print(f"Deleted collection '{args.collection}'.")
     return 0
+
+
+def handle_delete_records(args: Namespace) -> int:
+    try:
+        where = _parse_where_clause(args.where)
+    except ValueError as exc:
+        args.error_message = str(exc)
+        raise
+
+    deleted = delete_data(args.collection, where)
+    condition, value = next(iter(where.items()))
+    print(
+        f"Deleted {deleted} record(s) from collection '{args.collection}' "
+        f"where {condition}={value}."
+    )
+    return 0