how to fix “TypeError: string indices must be integers” when using cleaned_data?

full traceback

response = wrapped_callback(request, *callback_args, **callback_kwargs) File "C:\Users\P.A.N.D.E.M.I.C\Desktop\td11\newstudio\accounts\views.py", line 129, in reset_activation_key email = form.cleaned_data['email'] TypeError: string indices must be integers

this is view, where error blows up

def reset_activation_key(request):
    if request.user.is_authenticated():
        return redirect('/accounts/logout')
    if request.method   == "POST":
        form                    = ResetActivatioKey(request.POST or None)
        if form.is_valid():
            email               = form.cleaned_data['email']
            user                = User.objects.get(email=email)
            profile             = UserProfile.objects.get(user=user)
            if profile.is_active:
                return redirect('/accounts/login')
            if profile is not None and not profile.is_active == False :
                username        = user.username
                email_path      = "{0}/ResendEmail.txt".format(settings.EMAIL_FILE_PATH)
                get_secret_key  = activation_key_generator(username)
                profile.activation_key = get_secret_key
                profile.key_expires = (timezone.now() + datetime.timedelta(days=2)),
                profile.save()

                send_some_email(email, username, get_secret_key)
            return redirect('/accounts/login')
    else:
        form = ResetActivatioKey()
        context = {"form":form}
    return render(request, 'accounts/registration/reset_activation_key.html', context)

forms

class ResetActivatioKey(forms.Form):
    email = forms.EmailField(widget=forms.TextInput(attrs=dict(required=True, max_length=30)), label=_("Email address"))

    def clean(self):
        try:
            user = User.objects.get(email__iexact=self.cleaned_data['email'])
            return self.cleaned_data['email']
        except:
            raise forms.ValidationError('User with that email does not exist!')