>>> from django import forms
>>> class MyForm(forms.Form):
...     int = forms.IntegerField()
...
...
>>> form = MyForm(data={'int': 'asdf'})
>>> form.is_valid()
False
>>> form.as_p()
u'<ul class="errorlist"><li>Enter a whole number.</li></ul>\n<p><label for="id_int">Int:</label> <input id="id_int" name="int" type="number" value="asdf" /></p>'
>>> form.data.pop('int')
'asdf'
>>> form.as_p()
u'<ul class="errorlist"><li>Enter a whole number.</li></ul>\n<p><label for="id_int">Int:</label> <input id="id_int" name="int" type="number" /></p>'
>>>