pulling multiple records from mongo using flask and python

Question

I am still learning here and am currently trying to use FLASK to create to Restful interface

What I want to do is to pull out a collection of records from a mongo database. I have find_one() working fine and am now exploring how to itterate over a cursor

This code only displays a single record when I know there are at least 5

@app.route('/oer/api/v1.0/getType/', methods = ['GET'])
def getType():

    # Prepare a dictionary object to hold the result of any processing
    result = {}

    # Get hold of DB connection
    db_connection = getDbConnection()
    db = db_connection['OER']
    # Extract all records passed for the paramater that matches "Type": ie MOOC
    oerType = request.args.get("oerType");
    # test to see that there is something in the string if so try to get a record
    # Not doing this test yet lets get it working with a known record first 

    for d in db.oer_records.find({"Type":oerType}): 
        result.update(make_public_page(d))

    return jsonify(result)

So it works but only returns a single json document not a collection? I thought the result.update would append a new record each time through FYI make_public_page() removes BISON ID's to allow jsonify to work.

This is what it returns

{
    "Account No": 1,
    "Country/ continent": "Argentina",
    "Educational Level": "Schools",
    "Educational Level (ISCED)": "2|3",
    "End year": "",
    "Funders": "",
    "Geolocation": "",
    "Initiative HQ address": "",
    "Initiative HQ city": "",
    "Initiative URL": "http://www.gleducar.org.ar",
    "Type": "OER"
}

Any help appreciated.

Thanks

Sebastian · Accepted Answer · 2014-04-30 22:59:26Z

2

When using dict.update(dict2) you are adding dictionary dict2's key-values pairs in to dict which result in one big dict. What you might want to do is creating a list of dicts instead.

mylist = []
mylist.append(dict)

Translated to your code:

@app.route('/oer/api/v1.0/getType/', methods = ['GET'])
def getType():

    # Prepare a dictionary object to hold the result of any processing
    result = []  # create a list instead of dict

    # Get hold of DB connection
    db_connection = getDbConnection()
    db = db_connection['OER']
    # Extract all records passed for the paramater that matches "Type": ie MOOC
    oerType = request.args.get("oerType");
    # test to see that there is something in the string if so try to get a record
    # Not doing this test yet lets get it working with a known record first 

    for d in db.oer_records.find({"Type":oerType}): 
        result.append(make_public_page(d))  # append to the list of dicts

    return jsonify(items=result)

edited Apr 30, 2014 at 22:59

answered Apr 30, 2014 at 22:26

Sebastian

17.6k5 gold badges51 silver badges57 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Richard Over a year ago

Still very new to both python and flask do you mean add mylist = [] under the result ={} then mylist.append(make_public_page(d)) ?

Richard Over a year ago

I am getting ValueError: dictionary update sequence element #0 has length 36; 2 is required ? Thank you for your input !

Sebastian Over a year ago

@Richard change the last line to return jsonify(items=result). I forgot that jsonify cannot return arrays. make_public_page(d) returns a dict, right?

Richard Over a year ago

That did the trick thank you - now got to sort out a response for null seraches and how to split them into batches of 10 records but getting then to print as a set makes a big difference !

Collectives™ on Stack Overflow

pulling multiple records from mongo using flask and python

1 Answer 1

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related