Python libraries for validating data. Used for forms in many cases

There are several Python libraries available for validating data, including:

WTForms: WTForms is a flexible and powerful form handling library for Python. It provides a simple and intuitive interface for defining and validating forms, and it includes built-in support for a wide range of form fields, including text fields, checkboxes, and select fields.

Django Forms: Django Forms is a form handling library built into the Django web framework. It provides a simple and flexible interface for defining and validating forms, and it includes support for a wide range of form fields, including text fields, checkboxes, and select fields.

cerberus: Cerberus is a fast and lightweight data validation library for Python. It provides a simple and flexible interface for defining and validating data, and it includes support for a wide range of validation rules, including type checking, string formatting, and range checking.

marshmallow: marshmallow is a data serialization and validation library for Python. It provides a simple and flexible interface for defining and validating data, and it includes support for a wide range of data types, including strings, integers, and dates.

voluptuous: voluptuous is a data validation library for Python. It provides a simple and intuitive interface for defining and validating data, and it includes support for a wide range of validation rules, including type checking, string formatting, and range checking.

These are just a few examples of the many data validation libraries available for Python. The best library for your needs will depend on the specific requirements of your project, as well as your personal preferences and experience.