如何将pymongo字段结果保存为字符串

Question

I'm new to pymgono and I'm trying to understand how to process results. I have the following code inside my Client class which inserts documents in a localhost mongodb:

def InsertUser(self,
               userName: str,
               userDescription: str,
               userImage: str):
    # attempt to create or connect to users collection

    aUser = {"image_id": userImage,
             "name": userName,
             "description": userDescription}
    # insert randomly generated document into the database in the reviews collection
    result = self.myCollection.insert_one(aUser)

    print('Created:', aUser)
    print('at collection:', self.myCollection)
    print('with result:', result.inserted_id, '\n')

I then fetch specific fields using this method

def FindUser(self,
                 userName: str):
        print('found the following users named:',userName,'\n')
        myList=list()
        for i in self.myCollection.find({'name': userName},{'_id':0,'description':1}):
            myList.append(i)
        print('counted numbers in list=',len(myList))
        length=len(myList)
        for i in range(length):
            print(myList[i])

The find method prints myList[i] results as following:

counted numbers in list= 1
{'description': 'this is my description:'}

But what I really want to do is directly insert the description field into separate variable in string format like so:

counted numbers in list= 1
this is my description

How do I do that? Thanks for your time.

Answer 1

If I understand it correct userName should be unique for every user document in users collection, then using .find() would result in a single document in array, So instead of using .find() & iterating on it to get first document out of it, you can use .find_one() which would either return a single matched document or none if nothing matches with given filter :

def FindUser(self,
             userName: str):
    print('finding the following user named:', userName, '\n')
    dBUserResp = self.myCollection.find_one({'name': userName}, {'_id': 0, 'description': 1}):
    if dBUserResp:
        print(dBUserResp.description)
    # Above will return a string 'this is my description:'

    if not dBUserResp:
        print('No user found in DB')

Note : I had given only positive scenario where you get a result out of DB operation but in general you need to edit your code to check for any error with DB calls itself..

(Or)

If it's not the case & if you've multiple user documents with same userName then you can do :

descriptionString = myList[i]['description']
print(descriptionString) # which prints the description as string