切片 Django 查询集字段值

Question

My object has content field which is actually content of the article. I am passing it to template by using XHR. I don't want to slice content in front end. How can I slice it by giving a maximum character limit?

It is very long content so doing it in backend will help me to reduce my JSON size.

This is how my JSON looks like. I deleted content because it is very long. It will be in results list.

That's what I tried and it didn't work. It appends the new values to the end of the json file. But I want it to append each to each dictionary in results.

articles1 = Article.objects.all().values('title', 'tags', 'main_img', 'read_time', 'last_updated', 'slug').order_by('-last_updated')
    articles2 = Article.objects.all().values('content')
    short_content = [article['content'][3:100] for article in articles2]
    articles = list(chain(articles1, short_content))

Answer 1

You can pre-process each article's text field like this:

def shorten_content(article_values):
    article_values["content"] = article_values["content"][3:100]
    return article_values

article_queryset = Article.objects.values(
    'title', 'content', 'tags', 'main_img',
    'read_time', 'last_updated', 'slug'
).order_by('-last_updated')

articles = [
    shorten_content(article) for article in article_queryset
]