ComfyUI Node: Literal

Literal:

The Literal node is designed to convert a string representation of a Python literal into an actual sequence. This node is particularly useful when you need to input a sequence of values directly into your workflow without manually creating each element. By leveraging Python's ast.literal_eval function, the Literal node ensures that the input string is safely evaluated, allowing you to define complex sequences such as lists, tuples, dictionaries, and more. This capability can streamline your workflow by enabling the direct input of structured data, making it easier to manage and manipulate sequences within your AI art projects.

Literal Input Parameters:

literal

The literal parameter is a string input that represents the Python literal you wish to convert into a sequence. This parameter supports multiline input, allowing you to define complex structures such as lists, tuples, and dictionaries. The function of this parameter is to provide a textual representation of the sequence you want to create. The default value is an empty string (''), and there are no explicit minimum or maximum values, as it depends on the complexity of the Python literal you are defining. For example, you can input a list like "[1, 2, 3]" or a dictionary like "{'key': 'value'}".

Literal Output Parameters:

sequence

The sequence output parameter is the result of evaluating the literal input. It provides the actual sequence (e.g., list, tuple, dictionary) that was represented by the input string. This output is crucial for further processing within your workflow, as it allows you to work with structured data directly. The interpretation of this output depends on the input provided; for instance, if you input a list, the output will be a list, and if you input a dictionary, the output will be a dictionary.

Literal Usage Tips:

• Use the literal parameter to quickly input complex sequences without manually creating each element, saving time and reducing errors.
• Ensure that the input string is a valid Python literal to avoid evaluation errors. You can test your input in a Python interpreter before using it in the node.

Literal Common Errors and Solutions:

Invalid literal for ast.literal_eval

• Explanation: This error occurs when the input string is not a valid Python literal.
• Solution: Verify that your input string is correctly formatted as a Python literal. For example, ensure that lists are enclosed in square brackets ([]), dictionaries in curly braces ({}), and tuples in parentheses (()).

SyntaxError: unexpected EOF while parsing

• Explanation: This error happens when the input string is incomplete or improperly closed.
• Solution: Check that all brackets, braces, and parentheses are properly closed and that the input string is complete.

ValueError: malformed node or string

• Explanation: This error indicates that the input string contains characters or structures that ast.literal_eval cannot parse.
• Solution: Ensure that the input string only contains valid Python literals and does not include any unsupported characters or structures.