python 统计字典的个数:

只要将字典遍历一遍,然后累加即可得。

count = 0
 user = Question.query.filter(Question.id == question_id).first()
 for i in user.comments:
     count = count + 1
 print(u'小暖树')
 comment_nums = count
 return render_template('detail.html', question_model=question_model, comment_nums=comment_nums)