python 函数 pymongo 出错

Error in python function pymongo

这是一个 returns 在 post['date'] 行出错的函数。

这是错误:

in get_posts
    post['date'] = post['date'].strftime("%A, %B %d %Y at %I:%M%p")
KeyError: 'date'

这是什么意思?

这是函数:

def get_posts(self, num_posts):

    cursor = self.posts.find({},{}).limit(num_posts) # Using an empty itable for a placeholder so blog compiles before you make your changes
    # XXX HW 3.2 Work here to get the posts
    l = []

    for post in cursor:
        print post          
        post['date'] = post['date'].strftime("%A, %B %d %Y at %I:%M%p")
        if 'tags' not in post:
            post['tags'] = [] # fill it in if its not there already
        if 'comments' not in post:
            post['comments'] = []

        l.append({'title':post['title'], 'body':post['body'], 'post_date':post['date'],
                  'permalink':post['permalink'],
                  'tags':post['tags'],
                  'author':post['author'],
                  'comments':post['comments']})

    return l

KeyError: 'date' 表示 post 没有属性 date.