passing a variable with colon in function python

I am using this api.. whose function call looks like: ``` g.vertices.index.lookup(identifier="value") ``` Now note that idenitifier is a variable which I have not defined but is resoluted by api and value is a string. Something similar happens in pymongo api: http://api.mongodb.org/python/current/tutorial.html ``` db = client.test_database ``` is equal to ``` db = client["test_database"] ``` test_database in first case, even though user hasnt defined that variable.. but is understood by mongo that in my datastore, do i have a database called test_database or not.. Now, the issue I have is this: I have a colon in my datastore.. Which is to say it is like: ``` g.vertices.index.lookup(bad:identifier="value") ``` See.. the colon in the query.. And this api doesnt have that mongo type dictionary implementation.. I know, I should resolve this as in why I am getting this colon.. but this is what I am stuck at right now.. And the issue is because of that colon, I get ``` g.vertices.index.lookup(bad:identifier="value") ^ SyntaxError: invalid syntax ``` How do i resolve this