WTForms is a popular choice for form processing and validation in the Flask community. It uses a declarative approach to building forms (similar to how we defined our SQLAlchemy models), and supports a variety of different field types and validators.
Note
At the time of writing this book, WTForms 2.0 is still a development release, but should be the official release shortly. For that reason we will be using version 2.0 in this book.
Let's get started by installing WTForms into our blog project virtualenv:
(blog) $ pip install "wtforms>=2.0" Successfully installed wtforms Cleaning up...
We can verify that the installation succeeded by opening up a shell and checking the project version:
(blog) $ ./manage.py shell In [1]: import wtforms In [2]: wtforms.__version__ Out[2]: '2.0dev'
My version shows the development release since 2.0 has not been officially released yet.