allows for built-in ast unparse if present

dlt/common/reflection/utils.py

@@ -1,7 +1,14 @@
 import ast
 import inspect
 import astunparse
-from typing import Any, Dict, List, Optional, Sequence, Tuple, Union
+from typing import Any, Dict, List, Optional, Sequence, Tuple, Union, Callable
+
+try:
+    import astunparse
+
+    ast_unparse: Callable[[ast.AST], str] = astunparse.unparse
+except ImportError:
+    ast_unparse = ast.unparse  #  type: ignore[attr-defined, unused-ignore]
 
 from dlt.common.typing import AnyFun
 
@@ -25,7 +32,7 @@ def get_literal_defaults(node: Union[ast.FunctionDef, ast.AsyncFunctionDef]) ->
     literal_defaults: Dict[str, str] = {}
     for arg, default in zip(reversed(args), reversed(defaults)):
         if default:
-            literal_defaults[str(arg.arg)] = astunparse.unparse(default).strip()
+            literal_defaults[str(arg.arg)] = ast_unparse(default).strip()
 
     return literal_defaults
 
@@ -99,7 +106,7 @@ def rewrite_python_script(
             script_lines.append(source_script_lines[last_line][last_offset : node.col_offset])
 
         # replace node value
-        script_lines.append(astunparse.unparse(t_value).strip())
+        script_lines.append(ast_unparse(t_value).strip())
         last_line = node.end_lineno - 1
         last_offset = node.end_col_offset
 

dlt/destinations/dataset.py

@@ -3,12 +3,8 @@
 from contextlib import contextmanager
 
 from dlt import version
-
 from dlt.common.json import json
-
-from dlt.common.normalizers.naming.naming import NamingConvention
 from dlt.common.exceptions import MissingDependencyException
-
 from dlt.common.destination import AnyDestination
 from dlt.common.destination.reference import (
     SupportsReadableRelation,

dlt/destinations/impl/filesystem/filesystem.py

@@ -37,7 +37,7 @@
     TPipelineStateDoc,
     load_package as current_load_package,
 )
-from dlt.destinations.sql_client import DBApiCursor, WithSqlClient, SqlClientBase
+from dlt.destinations.sql_client import WithSqlClient, SqlClientBase
 from dlt.common.destination import DestinationCapabilitiesContext
 from dlt.common.destination.reference import (
     FollowupJobRequest,
@@ -63,7 +63,6 @@
 from dlt.destinations.impl.filesystem.configuration import FilesystemDestinationClientConfiguration
 from dlt.destinations import path_utils
 from dlt.destinations.fs_client import FSClientBase
-from dlt.destinations.dataset import ReadableDBAPIDataset
 from dlt.destinations.utils import verify_schema_merge_disposition
 
 INIT_FILE_NAME = "init"

dlt/reflection/script_visitor.py

@@ -3,8 +3,8 @@
 import astunparse
 from ast import NodeVisitor
 from typing import Any, Dict, List
-from dlt.common.reflection.utils import find_outer_func_def
 
+from dlt.common.reflection.utils import find_outer_func_def, ast_unparse
 
 import dlt.reflection.names as n
 
@@ -68,9 +68,9 @@ def visit_FunctionDef(self, node: ast.FunctionDef) -> Any:
             for deco in node.decorator_list:
                 # decorators can be function calls, attributes or names
                 if isinstance(deco, (ast.Name, ast.Attribute)):
-                    alias_name = astunparse.unparse(deco).strip()
+                    alias_name = ast_unparse(deco).strip()
                 elif isinstance(deco, ast.Call):
-                    alias_name = astunparse.unparse(deco.func).strip()
+                    alias_name = ast_unparse(deco.func).strip()
                 else:
                     raise ValueError(
                         self.source_segment(deco), type(deco), "Unknown decorator form"
@@ -87,7 +87,7 @@ def visit_FunctionDef(self, node: ast.FunctionDef) -> Any:
     def visit_Call(self, node: ast.Call) -> Any:
         if self._curr_pass == 2:
             # check if this is a call to any of known functions
-            alias_name = astunparse.unparse(node.func).strip()
+            alias_name = ast_unparse(node.func).strip()
             fn = self.func_aliases.get(alias_name)
             if not fn:
                 # try a fallback to "run" function that may be called on pipeline or source

dlt/sources/sql_database/arrow_helpers.py

@@ -4,9 +4,6 @@
 
 from dlt.common.configuration import with_config
 from dlt.common.destination import DestinationCapabilitiesContext
-from dlt.common.libs.pyarrow import (
-    row_tuples_to_arrow as _row_tuples_to_arrow,
-)
 
 
 @with_config
@@ -20,6 +17,8 @@ def row_tuples_to_arrow(
     is always the case if run within the pipeline. This will generate arrow schema compatible with the destination.
     Otherwise generic capabilities are used
     """
+    from dlt.common.libs.pyarrow import row_tuples_to_arrow as _row_tuples_to_arrow
+
     return _row_tuples_to_arrow(
         rows, caps or DestinationCapabilitiesContext.generic_capabilities(), columns, tz
     )