For django forms you can do this;
form = UserLoginForm(data=request.POST) #getting the whole data from the user.
user = form.save() #saving the details obtained from the user.
username = user.cleaned_data.get("username") #where "username" in parenthesis is the name of the Charfield (the variale name i.e, username = forms.Charfield(max_length=64))