how to pass complex string to pymongo for query by python? - python-3.x

Question

I need to filter the webserver requests and setting a query for pymongo, its not so simple as I need to have "and", or "or" functionality for multiple fields.
I have filtered the get request, got the parameters, built the string to be passed to db..find. But it throws error. I have identified the error as because I am forming a string like this to passed to the function, now as its a string and not actually a dict, its throwing an error. What is the right way of doing it?
Actually, I have to get something like: {$and:[{Title:{"$regex":"Hong Kong"}},{Url:{"$regex":"hong"}}]}{'_id':0, 'Body':0}
The get request I am sending is: http://127.0.0.1:5000/getRequest?Title="Hong Kong protest"&Url="hong" Now the below thing gives the exact required string, but it throws an error as its not supposed to be string. Please help.
#app.route('/getRequest', methods=['GET'])
def request():
global connection
args = request.args
if len(args) > 1:
search_str = ""
for key, val in args.items():
search_str += '{'+key+':{"$regex":'+str(val)+'}},'
search_str = search_str[:-1]
display_dict={'id':0, 'Body':0}
final_search_str = "{$and:["+search_str+"]},{'_id':0, 'Body':0}"
#return(final_search_str)
# query_str = request.args.get('query_string')
db = connection['test']
collection = db['collect1']
output = []
for s in collection.find(final_search_str):
output.append({'Title' : s['Title'], 'Url' : s['Url']})
It should be dict which should be passed to the function. Any better way to do this complex query via pymongo?

Answer 1

You can do this using re and bson.regex.Regex module.
http://api.mongodb.com/python/current/api/bson/regex.html
import re
from bson.regex import Regex
query = {}
for key, val in args.items():
pattern = re.compile(val)
regex = Regex.from_native(regex)
query[key] = regex
for s in collection.find(query):
output.append({'Title' : s['Title'], 'Url' : s['Url']})