only use astor for python compat

setup.py

@@ -21,7 +21,7 @@
         ],
     },
     install_requires=[
-        "astor; python_version < '3.9.0'",
+        "astor",
         "click",
         "croniter",
         "duckdb",

sqlmesh/utils/metaprogramming.py

@@ -12,6 +12,8 @@
 from enum import Enum
 from pathlib import Path
 
+from astor import to_source
+
 from sqlmesh.utils import trim_path, unique
 from sqlmesh.utils.errors import SQLMeshError
 from sqlmesh.utils.pydantic import PydanticModel
@@ -132,14 +134,6 @@ def join_source(lnum: int) -> str:
     raise SQLMeshError(f"Cannot find source for {obj}")
 
 
-def unparse(node: ast.Module) -> str:
-    if sys.version_info < (3, 9):
-        import astor
-
-        return astor.to_source(node).strip()
-    return ast.unparse(node).strip()
-
-
 def _parse_source(func: t.Callable) -> ast.Module:
     return ast.parse(textwrap.dedent(getsource(func)))
 
@@ -198,7 +192,7 @@ def normalize_source(obj: t.Any) -> str:
         elif isinstance(node, ast.arg):
             node.annotation = None
 
-    return unparse(root_node)
+    return to_source(root_node).strip()
 
 
 def build_env(obj: t.Any, *, env: t.Dict[str, t.Any], name: str, module: str) -> None:

tests/utils/test_metaprogramming.py

@@ -1,4 +1,3 @@
-import sys
 import typing as t
 from dataclasses import dataclass
 
@@ -116,8 +115,6 @@ def test_serialize_env() -> None:
     build_env(main_func, env=env, name="MAIN", module="tests")
     env = serialize_env(env, module="tests")  # type: ignore
 
-    lambda_no_args_padding = " " if sys.version_info < (3, 11) else ""
-
     assert env == {
         "MAIN": Executable(
             name="main_func",
@@ -171,7 +168,7 @@ def baz(self):
         "sqlglot": Executable(kind=ExecutableKind.IMPORT, payload="import sqlglot"),
         "my_lambda": Executable(
             path="test_metaprogramming.py",
-            payload=f"my_lambda = lambda{lambda_no_args_padding}: print('z')",
+            payload=f"my_lambda = lambda : print('z')",
         ),
         "other_func": Executable(
             path="test_metaprogramming.py",
@@ -206,7 +203,7 @@ def test_print_exception(mocker: MockerFixture):
 
     expected_message = f"""Traceback (most recent call last):
 
-  File "{__file__}", line 203, in test_print_exception
+  File "{__file__}", line 200, in test_print_exception
     eval("test_fun()", env)
 
   File "<string>", line 1, in <module>