如何在Django中按日期對對象進行分組？

Question

我試圖選擇文章表中的所有對象，並按他們的日期分組。我想它可能會類似於此：

articles = Article.objects.filter(pub_date__lte=datetime.date.today()).group_by(pub_date.day) 
articles = {'2010-01-01': (articleA, articleB, articleC...), 
      '2010-01-02': (article1, article2, article3...)...} 

Answer 1

這是一個工作的例子，ignacio建議使用itertools.groupby。

class Article(object): 
    def __init__(self, pub_date): 
     self.pub_date = pub_date 


if __name__ == '__main__': 
    from datetime import date 
    import itertools 
    import operator 

    # You'll use your Article query here instead: 
    # a_list = Article.objects.filter(pub_date__lte = date.today()) 
    a_list = [ 
     Article(date(2010, 1, 2)), 
     Article(date(2010, 2, 3)), 
     Article(date(2010, 1, 2)), 
     Article(date(2011, 3, 2)), 
    ] 


    keyfunc = operator.attrgetter('pub_date') 

    a_list = sorted(a_list, key = keyfunc) 
    group_list = [{ k.strftime('%Y-%m-%d') : list(g)} 
        for k, g in itertools.groupby(a_list, keyfunc)] 

    print group_list 

輸出：

[{'2010-01-02': [<__main__.Article object at 0xb76c4fec>, <__main__.Article object at 0xb76c604c>]}, {'2010-02-03': [<__main__.Article object at 0xb76c602c>]}, {'2011-03-02': [<__main__.Article object at 0xb76c606c>]}] 

Answer 2

itertools.groupby()

Answer 3

也許你應該在模板級別做呢？如果是這樣，你只需要這個：regroup tempalte tag