Python - Pymongo Insert and Update Documents

Use upsert option:

from pymongo import MongoClient
cl = MongoClient()
coll = cl["local"]["test2"]

data = [{"_id" : 1, "foo" : "HELLO"}, {"_id" : 2, "Blah" : "Bloh"}]
for d in data:
    coll.update({'_id':d['_id']}, d, True)

You can also use save

import pymongo
con = pymongo.MongoClient()
coll = con.db_name.collection_name

docs = [{"_id" : 1, "foo" : "HELLO"}, {"_id" : 2, "Blah" : "Bloh"}]

for doc in docs:
    coll.save(doc)