aboutsummaryrefslogtreecommitdiffstats
path: root/resources/libraries/python/enum_util.py
diff options
context:
space:
mode:
Diffstat (limited to 'resources/libraries/python/enum_util.py')
-rw-r--r--resources/libraries/python/enum_util.py70
1 files changed, 70 insertions, 0 deletions
diff --git a/resources/libraries/python/enum_util.py b/resources/libraries/python/enum_util.py
new file mode 100644
index 0000000000..f721936ee4
--- /dev/null
+++ b/resources/libraries/python/enum_util.py
@@ -0,0 +1,70 @@
+# Copyright (c) 2024 Cisco and/or its affiliates.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Utility functions for handling VPP API enum values from Robot."""
+
+
+from enum import Enum, IntEnum
+from typing import Type, Union
+
+
+# The return type is enum_class, but it is hard to explain that to pylint.
+def get_enum_instance(
+ enum_class: Type[Enum], value: Union[Enum, str, int, None]
+) -> Enum:
+ """Return an enum instance matching the string name.
+
+ In Robot, it is not convenient to construct Enum instances,
+ most values defined in Robot are strings.
+
+ This helper function can be used in Python L1 keywords
+ to convert string into the corresponding Enum instance.
+ Aliases are also recognized.
+
+ As a common shortcut, value is returned it it already is an instance.
+
+ Another convenience: None or empty string is processed as "NONE".
+
+ As an added benefit, support various Robot-like niceties,
+ like lower case, or dash or space instead of underscore.
+ Also strip the identifiers, this is mostly due to "3DES".
+ Enum instance cannot start with a number, so "_3DES" + strip is needed.
+
+ If the class is a subclass of IntEnum, int values
+ and (string) values convertable to int are also accepted as input.
+
+ :param enum_class: Class object instance of which should be returned.
+ :param value: String or any other recognized form of an enum instance.
+ :type enum_class: Type[Enum]
+ :type value: Union[enum_class, str, int, None]
+ :returns: The matching instance, if found.
+ :rtype: enum_class
+ :raises: ValueError if no matching instance is found.
+ """
+ if issubclass(enum_class, IntEnum):
+ try:
+ int_value = int(value)
+ return enum_class(int_value)
+ except (TypeError, ValueError):
+ pass
+ if isinstance(value, enum_class):
+ return value
+ if not value:
+ value = "NONE"
+ normalized_name = str(value).upper().replace("-", " ").replace("_", " ")
+ members = enum_class.__members__ # Includes aliases, useful for NONE.
+ for member_name in members:
+ if normalized_name.strip() == member_name.replace("_", " ").strip():
+ return members[member_name]
+ msg = f"Enum class {enum_class} does not have value {normalized_name!r}"
+ raise ValueError(msg)