EnumWithDict

EnumWithDict is a Python package that extends the standard library's Enum class to include to_dict, get_initial, and other class methods. This enhancement allows for the straightforward conversion of enum classes to dictionaries, easy access to the initial enum value, and additional functionalities such as retrieving enum values with a fallback option, validating mappings, and more.

Extends Enum with the Following Methods:

• to_dict: Convert an enum class to a dictionary representation, mapping member names to their values.
• get_initial: Retrieve the first value defined in the enum, useful for cases where a default or initial value is needed.
• get: Mimics the dictionary get method, allowing retrieval of enum values with an optional default fallback. Additionally, it supports an optional custom mapping dictionary for dynamically mapped value retrieval.
• validate_mapping_keys: Ensure that a provided mapping includes all enum values, raising an error for any missing mappings.
• map: Map enum members to values based on the provided dictionary.
• keys: Retrieve the keys of the enum class as a list or as a KeysView.
• values: Retrieve the values of the enum class as a list or as a ValuesView.

Installation

Install EnumWithDict using pip:

pip install enum-with-dict

Usage

Defining an Enum with EnumWithDict

from enum_with_dict import EnumWithDict

class Color(EnumWithDict):
    RED = 'red'
    GREEN = 'green'
    BLUE = 'blue'

Converting an Enum to a Dictionary

color_dict = Color.to_dict()
print(color_dict)
# Output: {'RED': 'red', 'GREEN': 'green', 'BLUE': 'blue'}

Getting the Initial Enum Value

initial_color = Color.get_initial()
print(initial_color)
# Output: 'red'

Using the get Method

Retrieve an enum value by its name, with an option to specify a default value if the name does not exist. Additionally, you can pass a custom mapping dictionary to retrieve a mapped value instead of the enum's default value.

Get a value for an existing key

print(Color.get('RED'))  # Output: 'red'

Get a value for a non-existing key with a default value

print(Color.get('PURPLE', default='unknown'))  # Output: 'unknown'

Get a value for a non-existing key, falling back to the initial value

print(Color.get('PURPLE'))  # Output: 'red'

Get a value using a custom mapping

You can also use a custom mapping dictionary to retrieve a value. This is useful when you need to map enum members to different values dynamically.

custom_mapping = {'RED': 'Rouge', 'GREEN': 'Vert', 'BLUE': 'Bleu'}
print(Color.get('RED', mapping=custom_mapping))  # Output: 'Rouge'

Ensuring Completeness of Mappings with validate_mapping_keys

Validate that a provided mapping covers all enum members.

# Assuming a partial mapping for demonstration
partial_mapping = {'RED': 'Rouge', 'GREEN': 'Vert'}

try:
    Color.validate_mapping_keys(partial_mapping)
except ValueError as e:
    print(e)
# Expected output: Missing mappings for: BLUE

Mapping Enum Members with map

Map enum members to values using the provided dictionary.

This mapping operation does not alter the values within the Enum itself; instead, it generates a new dictionary with the same keys and updated values.

Internally, validate_mapping_keys is invoked to confirm that the keys align with the Enum members, but the value types remain arbitrary.

💡 Helpful Hint: Using the .map method ensures that the mapping maintains the same keys as the Enum members, allowing for a direct correspondence. This method validates that all Enum members are accounted for in the mapping, preventing omissions or the inclusion of extraneous keys. It's a safeguard to ensure that your mapping is comprehensive and accurately reflects the Enum structure.

# Define the key mapping
key_mapping = {
    TestEnum.VALUE_1: "some_new_value",
    TestEnum.VALUE_2: "another_new_value",
    TestEnum.VALUE_3: "a new value"
}

# Perform the mapping and validate
mapped_values = TestEnum.map(key_mapping)

# ----- The above is equivalent to the following: -----

# Validate the mapped values
expected_values = {
    TestEnum.VALUE_1.name: "some_new_value",
    TestEnum.VALUE_2.name: "another_new_value",
    TestEnum.VALUE_3.name: "a new value"
}

assert mapped_values == expected_values

Retrieving Keys and Values with keys() and values()

Retrieve the keys and values of the enum class as a list or as a KeysView or ValuesView.

Get keys as a list

keys_list = Color.keys()

Get keys as a KeysView

keys_view = Color.keys(as_list=False)

Get values as a list

values_list = Color.values()

Get values as a ValuesView

values_view = Color.values(as_list=False)

LICENSE

EnumWithDict is released under the MIT License. See the LICENSE file for more details.