Remove runtime packaging dependency by simplifying SQLAlchemy version detection check

ibm_db_sa/base.py

@@ -29,13 +29,13 @@
 from sqlalchemy.sql import compiler
 from sqlalchemy.sql import operators
 from sqlalchemy.engine import default
-from sqlalchemy import __version__ as SA_Version
+from sqlalchemy import __version__ as SA_VERSION_STR
 from . import reflection as ibm_reflection
-from packaging import version
 
-SQLALCHEMY_VERSION = version.parse(sqlalchemy.__version__)
+m = re.match(r"^\s*(\d+)\.(\d+)", SA_VERSION_STR)
+SA_VERSION_MM = (int(m.group(1)), int(m.group(2))) if m else (0, 0)
 
-if SQLALCHEMY_VERSION >= version.parse("2.0"):
+if SA_VERSION_MM >= (2, 0):
     from sqlalchemy.sql.sqltypes import NullType, NULLTYPE, _Binary
     from sqlalchemy.sql.sqltypes import (
         ARRAY, BIGINT, BigInteger, BINARY, BLOB, BOOLEAN, Boolean,
@@ -68,8 +68,6 @@
         UserDefinedType, Variant
     )
 
-SA_Version = [int(ver_token) for ver_token in SA_Version.split('.')[0:2]]
-
 # as documented from:
 # http://publib.boulder.ibm.com/infocenter/db2luw/v9/index.jsp?topic=/com.ibm.db2.udb.doc/admin/r0001095.htm
 RESERVED_WORDS = set(
@@ -373,7 +371,7 @@ def visit_large_binary(self, type_, **kw):
 
 
 class DB2Compiler(compiler.SQLCompiler):
-    if SA_Version < [0, 9]:
+    if SA_VERSION_MM < (0, 9):
         def visit_false(self, expr, **kw):
             return '0'
 
@@ -550,7 +548,7 @@ def visit_function(self, func, result_map=None, **kwargs):
     def visit_cast(self, cast, **kw):
         type_ = cast.typeclause.type
 
-        if SQLALCHEMY_VERSION >= version.parse("2.0"):
+        if SA_VERSION_MM >= (2, 0):
             valid_types = (
                 CHAR, VARCHAR, CLOB, String, Text, Unicode, UnicodeText,
                 BLOB, LargeBinary, VARBINARY,
@@ -718,7 +716,7 @@ def create_table_constraints(self, table, **kw):
         return result
 
     def visit_create_index(self, create, include_schema=True, include_table_schema=True, **kw):
-        if SA_Version < [0, 8]:
+        if SA_VERSION_MM < (0, 8):
             sql = super(DB2DDLCompiler, self).visit_create_index(create, **kw)
         else:
             sql = super(DB2DDLCompiler, self).visit_create_index(create, include_schema, include_table_schema, **kw)
@@ -798,9 +796,9 @@ class DB2Dialect(default.DefaultDialect):
     supports_char_length = False
     supports_unicode_statements = False
     supports_unicode_binds = False
-    if SA_Version < [1, 4]:
+    if SA_VERSION_MM < (1, 4):
         returns_unicode_strings = False
-    elif SA_Version < [2, 0]:
+    elif SA_VERSION_MM < (2, 0):
         returns_unicode_strings = sa_types.String.RETURNS_CONDITIONAL
     else:
         returns_unicode_strings = True

ibm_db_sa/ibm_db.py

@@ -17,12 +17,14 @@
 # | Contributors: Jaimy Azle, Mike Bayer,Hemlata Bhatt                       |
 # +--------------------------------------------------------------------------+
 
-from sqlalchemy import __version__ as SA_Version
-SA_Version = [int(ver_token) for ver_token in SA_Version.split('.')[0:2]]
+import re
+from sqlalchemy import __version__ as SA_VERSION_STR
+m = re.match(r"^\s*(\d+)\.(\d+)", SA_VERSION_STR)
+SA_VERSION_MM = (int(m.group(1)), int(m.group(2))) if m else (0, 0)
 
 from .base import DB2ExecutionContext, DB2Dialect
 
-if SA_Version < [2,0]:
+if SA_VERSION_MM < (2, 0):
     from sqlalchemy import processors, types as sa_types, util
 else:
     from sqlalchemy import types as sa_types, util
@@ -36,7 +38,7 @@
 SQL_TXN_SERIALIZABLE = 8
 SQL_ATTR_TXN_ISOLATION = 108
 
-if SA_Version < [0, 8]:
+if SA_VERSION_MM < (0, 8):
     from sqlalchemy.engine import base
 else:
     from sqlalchemy.engine import result as _result
@@ -76,7 +78,7 @@ def pre_exec(self):
 
     def get_result_proxy(self):
         if self._callproc_result and self._out_parameters:
-            if SA_Version < [0, 8]:
+            if SA_VERSION_MM < (0, 8):
                 result = base.ResultProxy(self)
             else:
                 result = _result.ResultProxy(self)
@@ -89,7 +91,7 @@ def get_result_proxy(self):
 
             return result
         else:
-            if SA_Version < [0, 8]:
+            if SA_VERSION_MM < (0, 8):
                 result = base.ResultProxy(self)
             else:
                 result = _result.ResultProxy(self)
@@ -115,7 +117,7 @@ class DB2Dialect_ibm_db(DB2Dialect):
         }
     )
 
-    if SA_Version < [2, 0]:
+    if SA_VERSION_MM < (2, 0):
         @classmethod
         def dbapi(cls):
             """ Returns: the underlying DBAPI driver module

ibm_db_sa/ibm_db_as400.py

@@ -1,7 +1,9 @@
-from sqlalchemy import __version__ as SA_Version
-SA_Version = [int(ver_token) for ver_token in SA_Version.split('.')[0:2]]
+import re
+from sqlalchemy import __version__ as SA_VERSION_STR
+m = re.match(r"^\s*(\d+)\.(\d+)", SA_VERSION_STR)
+SA_VERSION_MM = (int(m.group(1)), int(m.group(2))) if m else (0, 0)
 from .base import DB2ExecutionContext, DB2Dialect
-if SA_Version < [2,0]:
+if SA_VERSION_MM < (2, 0):
     from sqlalchemy import processors, types as sa_types, util
 else:
     from sqlalchemy import types as sa_types, util

pyproject.toml

@@ -1,3 +1,3 @@
 [build-system]
-requires = ["setuptools>=42", "wheel", "packaging>=20.0"]
+requires = ["setuptools>=42", "wheel"]
 build-backend = "setuptools.build_meta"

setup.py

@@ -11,9 +11,9 @@
 
 readme = os.path.join(os.path.dirname(__file__), 'README.md')
 if 'USE_PYODBC' in os.environ and os.environ['USE_PYODBC'] == '1':
-    require = ['sqlalchemy>=0.7.3', 'packaging>=20.0']
+    require = ['sqlalchemy>=0.7.3']
 else:
-    require = ['sqlalchemy>=0.7.3','ibm_db>=2.0.0', 'packaging>=20.0']
+    require = ['sqlalchemy>=0.7.3','ibm_db>=2.0.0']
 
 
 setup(