python – Mongoengine – 如何执行“保存新项目或增量计数器” *** 作？

概述我在一个网络抓取项目中使用MongoEngine.我想跟踪我在所有抓取的网页上遇到的所有图像. 为此,我存储图像src URL和图像遇到的次数. MongoEngine模型定义如下： class ImagesUrl(Document): """ Model representing images encountered during web-scraping. When an i 我在一个网络抓取项目中使用MongoEngine.我想跟踪我在所有抓取的网页上遇到的所有图像.

为此,我存储图像src URL和图像遇到的次数.

MongoEngine模型定义如下：

class ImagesUrl(document):    """ Model representing images encountered during web-scraPing.    When an image is encountered on a web-page during scraPing,we store its url and the number of times it has been    seen (default counter value is 1).    If the image had been seen before,we do not insert a new document    in collection,but merely increment the corresponding counter value.    """    # The url of the image. There cannot be any duplicate.    src = URLFIEld(required=True,unique=True)    # counter of the total number of occurences of the image during    # the datamining process    counter = IntFIEld(min_value=0,required=True,default=1)

我正在寻找实现“保存或增量”过程的正确方法.

到目前为止,我正在以这种方式处理它,但我觉得可能有更好的,内置的方式使用MongoEngine：

def save_or_increment(self):    """ If it is the first time the image has been encountered,insert        its src in mongo,along with a counter=1 value.        If not,increment its counter value by 1.    """     # check if item is already stored    # if not,save a new item    if not ImagesUrl.objects(src=self.src):        ImagesUrl(            src=self.src,counter=self.counter,).save()    else:        # if item already stored in Mongo,just increment its counter        ImagesUrl.objects(src=self.src).update_one(inc__counter=1)

有没有更好的方法呢？

非常感谢您的宝贵时间.

解决方法 你应该能够做一个 upsert,例如：

ImagesUrl.objects(src=self.src).update_one(                                  upsert=True,inc__counter=1,set__src=self.src)

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