langchain[patch]: Migrate top level files to use optional langchain community (#21152)

Migrate a few top level files to treat langchain community as an optional dependency

libs/langchain/langchain/cache.py

@@ -1,21 +1,56 @@
-from langchain_community.cache import (
+from typing import TYPE_CHECKING, Any
-    AstraDBCache,
+
-    AstraDBSemanticCache,
+from langchain._api import create_importer
-    AzureCosmosDBSemanticCache,
+
-    CassandraCache,
+if TYPE_CHECKING:
-    CassandraSemanticCache,
+    from langchain_community.cache import (
-    FullLLMCache,
+        AstraDBCache,
-    FullMd5LLMCache,
+        AstraDBSemanticCache,
-    GPTCache,
+        AzureCosmosDBSemanticCache,
-    InMemoryCache,
+        CassandraCache,
-    MomentoCache,
+        CassandraSemanticCache,
-    RedisCache,
+        FullLLMCache,
-    RedisSemanticCache,
+        FullMd5LLMCache,
-    SQLAlchemyCache,
+        GPTCache,
-    SQLAlchemyMd5Cache,
+        InMemoryCache,
-    SQLiteCache,
+        MomentoCache,
-    UpstashRedisCache,
+        RedisCache,
-)
+        RedisSemanticCache,
+        SQLAlchemyCache,
+        SQLAlchemyMd5Cache,
+        SQLiteCache,
+        UpstashRedisCache,
+    )
+
+# Create a way to dynamically look up deprecated imports.
+# Used to consolidate logic for raising deprecation warnings and
+# handling optional imports.
+DEPRECATED_LOOKUP = {
+    "FullLLMCache": "langchain_community.cache",
+    "SQLAlchemyCache": "langchain_community.cache",
+    "SQLiteCache": "langchain_community.cache",
+    "UpstashRedisCache": "langchain_community.cache",
+    "RedisCache": "langchain_community.cache",
+    "RedisSemanticCache": "langchain_community.cache",
+    "GPTCache": "langchain_community.cache",
+    "MomentoCache": "langchain_community.cache",
+    "InMemoryCache": "langchain_community.cache",
+    "CassandraCache": "langchain_community.cache",
+    "CassandraSemanticCache": "langchain_community.cache",
+    "FullMd5LLMCache": "langchain_community.cache",
+    "SQLAlchemyMd5Cache": "langchain_community.cache",
+    "AstraDBCache": "langchain_community.cache",
+    "AstraDBSemanticCache": "langchain_community.cache",
+    "AzureCosmosDBSemanticCache": "langchain_community.cache",
+}
+
+_import_attribute = create_importer(__package__, deprecated_lookups=DEPRECATED_LOOKUP)
+
+
+def __getattr__(name: str) -> Any:
+    """Look up attributes dynamically."""
+    return _import_attribute(name)
+
 
 __all__ = [
     "FullLLMCache",

libs/langchain/langchain/requests.py

@@ -1,5 +1,31 @@
 """DEPRECATED: Kept for backwards compatibility."""
-from langchain_community.utilities import Requests, RequestsWrapper, TextRequestsWrapper
+from typing import TYPE_CHECKING, Any
+
+from langchain._api import create_importer
+
+if TYPE_CHECKING:
+    from langchain_community.utilities import (
+        Requests,
+        RequestsWrapper,
+        TextRequestsWrapper,
+    )
+
+# Create a way to dynamically look up deprecated imports.
+# Used to consolidate logic for raising deprecation warnings and
+# handling optional imports.
+DEPRECATED_LOOKUP = {
+    "Requests": "langchain_community.utilities",
+    "RequestsWrapper": "langchain_community.utilities",
+    "TextRequestsWrapper": "langchain_community.utilities",
+}
+
+_import_attribute = create_importer(__package__, deprecated_lookups=DEPRECATED_LOOKUP)
+
+
+def __getattr__(name: str) -> Any:
+    """Look up attributes dynamically."""
+    return _import_attribute(name)
+
 
 __all__ = [
     "Requests",

libs/langchain/langchain/serpapi.py

@@ -1,4 +1,24 @@
 """For backwards compatibility."""
-from langchain_community.utilities.serpapi import SerpAPIWrapper
+from typing import TYPE_CHECKING, Any
 
-__all__ = ["SerpAPIWrapper"]
+from langchain._api import create_importer
+
+if TYPE_CHECKING:
+    from langchain_community.utilities import SerpAPIWrapper
+
+# Create a way to dynamically look up deprecated imports.
+# Used to consolidate logic for raising deprecation warnings and
+# handling optional imports.
+DEPRECATED_LOOKUP = {"SerpAPIWrapper": "langchain_community.utilities"}
+
+_import_attribute = create_importer(__package__, deprecated_lookups=DEPRECATED_LOOKUP)
+
+
+def __getattr__(name: str) -> Any:
+    """Look up attributes dynamically."""
+    return _import_attribute(name)
+
+
+__all__ = [
+    "SerpAPIWrapper",
+]

libs/langchain/langchain/sql_database.py

@@ -1,4 +1,24 @@
 """Keep here for backwards compatibility."""
-from langchain_community.utilities.sql_database import SQLDatabase
+from typing import TYPE_CHECKING, Any
 
-__all__ = ["SQLDatabase"]
+from langchain._api import create_importer
+
+if TYPE_CHECKING:
+    from langchain_community.utilities import SQLDatabase
+
+# Create a way to dynamically look up deprecated imports.
+# Used to consolidate logic for raising deprecation warnings and
+# handling optional imports.
+DEPRECATED_LOOKUP = {"SQLDatabase": "langchain_community.utilities"}
+
+_import_attribute = create_importer(__package__, deprecated_lookups=DEPRECATED_LOOKUP)
+
+
+def __getattr__(name: str) -> Any:
+    """Look up attributes dynamically."""
+    return _import_attribute(name)
+
+
+__all__ = [
+    "SQLDatabase",
+]