How do you set a default value for a WTForms SelectField?

When attempting to set the default value of a SelectField with WTForms, I pass in value to the 'default' parameter like so.

class TestForm(Form):
  test_field = SelectField("Test: ", choices=[(1, "Abc"), (2, "Def")], default=2)

I have also tried the following.

class TestForm(Form):
  test_field = SelectField("Test: ", choices=[(1, "Abc"), (2, "Def")], default=(2, "Def"))

Neither set the default selected field to "Def." This works for other kinds of Fields such as TextField. How do you set the default value for a SelectField?'

Solution 1:

I believe this problem is caused by the Field's data attribute overriding the default with something that WTForms doesn't understand (e.g. a DB model object -- it expects an int). This would happen if you have populated your form in the constructor like so:

form = PostForm(obj=post)

the solution is to manually set the data attribute after the form has been populated:

form = PostForm(obj=post)
form.category.data = (post.category.id
                      if page.category
                      else 0) # I make 0 my default

Solution 2:

The first way you posted is correct, and it works for me. The only explanation for it not working can be that you are running an older version of WTForms, it worked for me on 1.0.1