PlaceholderAttributeMixin

forms.py

class PlaceholderAttributeMixin(object):
    def __init__(self, *args, **kwargs):
        super(PlaceholderAttributeMixin, self).__init__(*args, **kwargs)
        for field_name in self.fields:
            field = self.fields.get(field_name)  
            if field:
                if type(field.widget) in (forms.TextInput, forms.DateInput):
                    field.widget = forms.TextInput(attrs={'placeholder': field.label})
                elif type(field.widget) in (forms.PasswordInput,):
                    field.widget = forms.PasswordInput(attrs={'placeholder': field.label})

# Usage:

from registration.forms import RegistrationForm
from helpers.forms import PlaceholderAttributeMixin

class PlaceholderRegistrationForm(PlaceholderAttributeMixin, RegistrationForm):
	pass

## PlaceholderRegistrationForm now inserts html5 placeholder attribute in all text, date and password inputs.