class wtforms.fields.SelectField(default field arguments, choices=[], coerce=unicode, option_widget=None)
Select fields keep a choices property which is a sequence of (value, label) pairs. The value portion can be any type in theory, but as form data is sent by the browser as strings, you will need to provide a function which can coerce the string representation back to a comparable object.
Select fields with static choice values:
class PastebinEntry(Form):
language = SelectField(u'Programming Language', choices=[('cpp', 'C++'), ('py', 'Python'), ('text', 'Plain Text')])