Validate interface variable names

Signed-off-by: ddl-rliu <richard.liu@dominodatalab.com>

flytekit/core/interface.py

@@ -3,6 +3,7 @@
 import collections
 import copy
 import inspect
+import re
 import typing
 from collections import OrderedDict
 from typing import Any, Dict, Generator, List, Optional, Tuple, Type, TypeVar, Union, cast
@@ -21,6 +22,7 @@
 from flytekit.models.literals import Literal, Scalar, Void
 
 T = typing.TypeVar("T")
+_PYTHON_VARIABLE_NAME_REGEX = re.compile(r'^[a-zA-Z_][a-zA-Z0-9_]*$')
 
 
 def repr_kv(k: str, v: Union[Type, Tuple[Type, Any]]) -> str:
@@ -261,6 +263,12 @@ def transform_interface_to_typed_interface(
             interface.docstring.output_descriptions, interface.outputs
         )
 
+    # Assert valid interface variable names
+    for key in interface.inputs.keys():
+        assert _PYTHON_VARIABLE_NAME_REGEX.match(key), f"Invalid input name: '{key}'. Inputs must be valid Python variable names."
+    for key in interface.outputs.keys():
+        assert _PYTHON_VARIABLE_NAME_REGEX.match(key), f"Invalid output name: '{key}'. Outputs must be valid Python variable names."
+
     inputs_map = transform_variable_map(interface.inputs, input_descriptions)
     outputs_map = transform_variable_map(interface.outputs, output_descriptions)
     verify_outputs_artifact_bindings(interface.inputs, outputs_map, allow_partial_artifact_id_binding)