我希望answer here与我遇到的问题有关，但不幸的是，它不一样，我无法使用它来解决问题。我还尝试遵循method here，这也不能证明成功解决这个特定的问题。

问题是：我尝试使用一个简单的表单来创建一个新的对象。一些信息来自用户，一些信息来自系统。当我处理POST请求时，使用简单的print语句，我可以看到表单是有效的，并且它有正确的数据。但是当我去保存时，它告诉我对象是None，所以它不保存任何东西。

下面是：

• views.py
• forms.py
• models.py
• template.html

我错过了什么？谢谢！

查看次数.py

def add_set_to_active_workout(request):
    workout = get_active_workout()
    if request.method == "POST":
        form = SetForm(request.POST)
        if form.is_valid():
            print(f"Cleaned data is: {form.cleaned_data}") # This prints what I'd expect, namely, the user submitted data. 
            set = form.save(commit=False)
            set.workout = workout
            print(f"Set is {set}") # This prints: Set is Set object (None)
            set.save()
            print("set saved")
            return HttpResponseRedirect(reverse("log:active_workout"))
        else:
            return render(request, "log/active_workout.html", {
                "set_form": form,
                'workout': workout
            })
    else:
        return render(request, "log/active_workout.html", {
            "set_form": SetForm(), 'workout': workout,
        })

**print语句print(f"Set is {set}") Set is Set object (none)，这是要解决的问题。**下面是确切的print语句：

Cleaned data is: {'exercise': <Exercise: Deadlift>, 'actual_weight': 225.0, 'actual_reps': 12, 'actual_difficulty': 'easy'}
Set is Set object (None)
set saved
forms.py

class SetForm(forms.ModelForm):
    class Meta:
        model = Set
        fields = ['exercise', 'actual_weight', 'actual_reps', 'actual_difficulty']

models.py

class Set(models.Model):
    exercise = models.ForeignKey(Exercise, related_name="sets", on_delete=models.SET("Exercise Deleted!"))
    workout = models.ForeignKey(Workout, related_name="sets", on_delete=models.CASCADE)
    actual_reps = models.PositiveSmallIntegerField()
    actual_weight = models.FloatField()

    difficulty_options = (
        ("easy", "easy"),
        ("medium", "medium"),
        ("hard", "hard")
    )
    actual_difficulty = models.CharField(choices=difficulty_options, max_length=6)

    set_complete = models.DateTimeField(auto_now_add=True)

template.html

<h2>Add a Set:</h2>
<form action="{% url 'log:add_set_to_active_workout' %}" method="POST">
    {% csrf_token %}
    {{ set_form.as_p }}
    <input type="submit" value="Save Set" class="btn btn-secondary">
</form>