[CG-10935] fix: issues with unpacking (#724)

# Motivation

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# Content

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# Testing

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# Please check the following before marking your PR as ready for review

- [ ] I have added tests for my changes
- [ ] I have updated the documentation or added new documentation as
needed

---------

Co-authored-by: tomcodgen <191515280+tomcodgen@users.noreply.github.com>

Author: tomcodgen

src/codegen/sdk/python/assignment.py

@@ -12,6 +12,7 @@
 from codegen.sdk.python.symbol import PySymbol
 from codegen.sdk.python.symbol_groups.comment_group import PyCommentGroup
 from codegen.shared.decorators.docs import noapidoc, py_apidoc
+from codegen.shared.logging.get_logger import get_logger
 
 if TYPE_CHECKING:
     from tree_sitter import Node as TSNode
@@ -20,6 +21,8 @@
     from codegen.sdk.core.node_id_factory import NodeId
     from codegen.sdk.python.statements.assignment_statement import PyAssignmentStatement
 
+logger = get_logger(__name__)
+
 
 @py_apidoc
 class PyAssignment(Assignment["PyAssignmentStatement"], PySymbol):
@@ -152,6 +155,9 @@ def remove(self, delete_formatting: bool = True, priority: int = 0, dedupe: bool
                     else:
                         self.parent._values_scheduled_for_removal = []
                 else:
+                    if name.source == "_":
+                        logger.warning("Attempting to remove '_' in unpacking, command will be ignored. If you wish to remove the statement, remove the other remaining variable(s)!")
+                        return
                     transaction_count = self._active_transactions_on_assignment_names(TransactionPriority.Edit)
                     throwaway = [asgnmt.name == "_" for asgnmt in self.parent.assignments].count(True)
                     # Only edit if we didn't already omit all the other assignments, otherwise just remove the whole thing

tests/unit/codegen/sdk/python/expressions/test_unpacking.py

@@ -1,5 +1,11 @@
+from typing import TYPE_CHECKING
+from unittest.mock import patch
+
 from codegen.sdk.codebase.factory.get_session import get_codebase_session
 
+if TYPE_CHECKING:
+    from codegen.sdk.core.file import SourceFile
+
 
 def test_remove_unpacking_assignment(tmpdir) -> None:
     # language=python
@@ -155,3 +161,27 @@ def test_remove_unpacking_assignment_num(tmpdir) -> None:
 
         assert len(file2.symbols) == 0
         assert file2.source == """"""
+
+
+@patch("codegen.sdk.python.assignment.logger")
+def test_unpacking_function_with_underscore_removal(mock_logger, tmpdir: str) -> None:
+    # language=python
+    content1 = """
+    args, _ = parser.parse_known_args() ##args gets deleted
+    with open(args.template_path) as f:
+        print('test')
+    """
+    with get_codebase_session(
+        tmpdir=tmpdir,
+        files={
+            "file1.py": content1,
+        },
+    ) as codebase:
+        file1: SourceFile = codebase.get_file("file1.py")
+
+        for symbol in codebase.symbols:
+            if not symbol.usages:
+                symbol.remove()
+        codebase.commit()
+        assert len(file1.symbols) != 0
+        assert mock_logger.warning.call_count == 1