How can I use 'Not Like' operator in MongoDB

I can use the SQL Like Operator using pymongo,

db.test.find({'c':{'$regex':'ttt'}})

But how can I use Not Like Operator?

I tried

db.test.find({'c':{'$not':{'$regex':'ttt'}})

but got error:

OperationFailure: $not cannot have a regex

From the docs:

The $not operator does not support operations with the $regex operator. Instead use // or in your driver interfaces, use your language’s regular expression capability to create regular expression objects. Consider the following example which uses the pattern match expression //:

db.inventory.find( { item: { $not: /^p.*/ } } )

EDIT (@idbentley):

{$regex: 'ttt'} is generally equivalent to /ttt/ in mongodb, so your query would become:

db.test.find({c: {$not: /ttt/}}

EDIT2 (@KyungHoon Kim):

In python, below one works:

'c':{'$not':re.compile('ttt')}

You can do with regex which does not contain a word. Also, you can use $options => i for case of insensitive search.

Doesn't Contain string

db.collection.find({name:{'$regex' : '^((?!string).)*$', '$options' : 'i'}})

Exact case insensitive string

db.collection.find({name:{'$regex' : '^string$', '$options' : 'i'}})

Starts with string

db.collection.find({name:{'$regex' : '^string', '$options' : 'i'}})

Ends with string

db.collection.find({name:{'$regex' : 'string$', '$options' : 'i'}})

Contains string

db.collection.find({name:{'$regex' : 'string', '$options' : 'i'}})

Keep this as a bookmark, and a reference for any other alterations you may need. http://www.cheatography.com/davechild/cheat-sheets/regular-expressions/