Add support to psycopg 3

Author: jairhenrique

dj_db_conn_pool/backends/postgresql/mixins.py

@@ -1,12 +1,18 @@
 # coding: utf-8
+import importlib
+
+try:
+    importlib.import_module("psycopg")
+    from sqlalchemy.dialects.postgresql.psycopg import PGDialect_psycopg as PGDialect
+except ModuleNotFoundError:
+    from sqlalchemy.dialects.postgresql.psycopg2 import PGDialect_psycopg2 as PGDialect
 
-from sqlalchemy.dialects.postgresql.psycopg2 import PGDialect_psycopg2
 
 from dj_db_conn_pool.core.mixins import PersistentDatabaseWrapperMixin
 
 
 class PGDatabaseWrapperMixin(PersistentDatabaseWrapperMixin):
-    class SQLAlchemyDialect(PGDialect_psycopg2):
+    class SQLAlchemyDialect(PGDialect):
         pass
 
     def get_new_connection(self, conn_params):

pyproject.toml

@@ -44,6 +44,8 @@ mysql = ["mysqlclient>=1.3.0"]
 odbc = ["pyodbc>=4.0.34"]
 oracle = ["cx-Oracle>=6.4.1"]
 postgresql = ["psycopg2>=2.8.6"]
+psycopg2 = ["psycopg2>=2.8.6"]
+psycopg3 = ["psycopg>=3"]
 
 [build-system]
 requires = ["setuptools"]