python - Why does the program stop executing at this point: if isinstance(item, AnItem): This sentence is obviously true, but it will not be executed at this point.

Question

I defined AnItem in items

It is also defined in spider.py using item = AnItem().

Why the above: if isinstance(item, AnItem): What follows this sentence will not be executed.

Explanation: if isinstance(item, AnItem): It is false, I don’t know why?

I look at other people’s code. There are also examples on the Internet that are written like this

I don’t know what I wrote wrong?

class AnPipeline(object):
    def process_item(self, item, spider):
        print ('process_item1111111111111111111111111111')
        if isinstance(item, AnItem):
            print ('process_item222222222222222222222222222')
            title = item['title']
            content = item['content']
            Sql.insert_data_all(title, content)
            print (u'存完一条信息aaaaaaaaaaaa')
            return item

Answer 1

Is it true or false? Can’t you output it to see?

Answer 2

if isinstance(item, AnItem):

    print ('zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz')
else:
    print ('jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj')

Tested it using the above statement in pipelines.py: output jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj
I don’t know what went wrong.
According to normal logic, it is defined in spiders.py: item = ZbaqcnItem()
Everything that should be imported is imported. Then it's in pipelines.py. It should be true?

Now I feel that there should be a problem with the import item?

I import like this in anspiders.py:
from aqccncn.items import AnItem
Always prompt an error. ImportError: No module named items
I searched online for a long time and couldn’t find a feasible solution.
Have no choice but to use the following method.

Then I created items.py in the spiders file
I imported it using from items import AnItem.

Then the later if isinstance(item, AnItem): is False.

Is this the reason?

Finally——————————————————————————————————————————————
Modified at 2016/04/29 18:04:

——————————————————————————————

Thank you all. Already solved. It turns out that at the beginning, from aaaa.items import AnItem always prompted an error. I created an items.py in the spiders file again, so the imported items.py is not the same, so the AnItem() is not the same either.

But there is another question:

If you create the items.py file in the same directory as the settgins.py file in the spiders folder. Why import like this: from AnAnAn.items import AnItem will prompt: ImportError: No module named AnAnAn.items?
In the AnAnAn folder, there is obviously the items.py generated by default, and the corresponding code is added to it.

What’s the problem with this? Thank you.