pymongo insert if not exists code example

Example: pymongo insert if not exists

Sounds like you want to do an "upsert". MongoDB has built-in support for this. Pass an extra parameter to your update() call: {upsert:true}. For example:

key = {'key':'value'}
data = {'key2':'value2', 'key3':'value3'};
coll.update(key, data, upsert=True); #In python upsert must be passed as a keyword argument
This replaces your if-find-else-update block entirely. It will insert if the key doesn't exist and will update if it does.

Before:

{"key":"value", "key2":"Ohai."}
After:

{"key":"value", "key2":"value2", "key3":"value3"}
You can also specify what data you want to write:

data = {"$set":{"key2":"value2"}}
Now your selected document will update the value of "key2" only and leave everything else untouched.