def get_expression(request): if request.method == 'POST': form = ExpressionForm(request.POST) if form.is_valid(): try: expression = form.cleaned_data['expression'] print form.cleaned_data['expression'] e2 = Expression() e2.expression_string = str(form.cleaned_data['expression']) e = Evaluator() result = e.evaluate_string(expression) e2.expression_result = result e2.save() print result return render(request, 'result.html', {'result': result}) except: result = 'Wrong input! Try again.' return render(request, 'result.html', {'result': result}) else: form = ExpressionForm() return render(request, 'index.html', {'form': form})