如何查询和排序python中嵌套的mongodb信息？

Question

I have the following code:

myd = mergedCollection.find(myquery).sort("Price")
print("MY D: "+str(myd))
shoes = myd[0]["theAssociatedShoes"]
print("Shoes: "+ str(shoes))

With the output:

MY D: <pymongo.cursor.Cursor object at 0x05859538>
Shoes: [{'Title': 'Nike Cosmic Unity "Amalgam"', 'Price': 160, 'Currency': 'USD', 'Picture': 'https://static.nike.com/a/images/t_default/3bca4f51-f2e4-4948-a665-27e03eea4ddd/cosmic-unity-amalgam-basketball-shoe-nDHKr4.png', 'Link': 'nike.com/t/cosmic-unity-amalgam-basketball-shoe-nDHKr4/DA6725-500', 'Brand': 'nike'}, {'Title': 'Ultraboost 21 Shoes', 'Price': 180, 'Currency': ' USD', 'Picture': 'https://assets.adidas.com/images/w_280,h_280,f_auto,q_auto:sensitive/3728ddf5b7dc4a2ca3e3ac7d0106c5a1_9366/ultraboost-21-shoes.jpg', 'Link': 'adidas.com/us/ultraboost-21-shoes/FY0350.html', 'Brand': 'adidas'}, {'Title': 'Fresh', 'Price': 129, 'Currency': ' USD', 'Picture': 'https://nb.scene7.com/is/image/NB/m880f11_nb_02_i?$pdpflexf2$&wid=440&hei=440', 'Link': 'newbalance.com/pd/fresh-foam-880v11/M880V11-33418.html', 'Brand': 'newbalance'}, {'Title': 'Jordan Delta Breathe', 'Price': 130, 'Currency': 'USD', 'Picture': 'https://static.nike.com/a/images/t_default/b54eef6b-6dd5-4c07-9b09-901ab9d7b01a/jordan-delta-breathe-mens-shoe-2ggX3h.png', 'Link': 'nike.com/t/jordan-delta-breathe-mens-shoe-2ggX3h/CW0783-901', 'Brand': 'jordan'},...]
     ...

How come the Shoes are not sorted by price here? I have also tried using this code:

myd = mergedCollection.find(myquery)[0]["theAssociatedShoes"].sort("Price")

But that throws a syntax error. I've also tried this solution to no avail.

myd = mergedCollection.find(myquery).sort("theAssociatedShoes.Price", -1)

Answer 1

Looking at your code, the data you are interested in is all in one record. MongoDB's sort only works across multiple records. To get the results in price order, use python's sorted built-in function and a lambda expression.

myd = collection.find()
for record in sorted(myd[0]["theAssociatedShoes"], key=lambda price: price['Price']):
    print(record)