FileExtensionValidator

This class provides a mechanism to validate that a file's extension matches a predefined list of permitted formats. It extracts the extension from a file object and raises a validation error with a customizable message and code if the extension is not allowed. The validator supports case-insensitive comparisons and can be used as a callable in validation pipelines.

Attributes

Attribute	Type	Description
message	string = File extension “%(extension)s” is not allowed. Allowed extensions are: %(allowed_extensions)s.	The error message used when the file extension is not found in the allowed list, supporting placeholders for extension and allowed_extensions.
code	string = invalid_extension	The fallback error code used to identify the validation failure in exception handling.

---

Constructor

Signature

def FileExtensionValidator(
    allowed_extensions: list = None,
    message: string,
    code: string
) - > null

Parameters

Name	Type	Description
allowed_extensions	list = None	A list of allowed file extensions. Extensions are converted to lowercase.
message	string	Custom error message to be used when validation fails. Defaults to a predefined message.
code	string	Custom error code to be used when validation fails. Defaults to 'invalid_extension'.

---