What do you mean by "elements"?
If you want a dict of key-value pairs with keys ≥6, Python 2.7+ and 3.x support dict comprehensions.
{ k: v for k, v in mydict.items() if k >= 6 }
You can get this in earlier versions of Python
dict( (k, v) for k, v in mydict.items() if k >= 6 ) # Python 2.4+
dict([(k, v) for k, v in mydict.items() if k >= 6]) # Python 2.0+
by using expression generators or list comprehensions.
If you want a list of keys only,
[ k for k in mydict.keys() if k >= 6 ]
filter( lambda k: k >= 6, mydict.keys() )
Similarly, if you want a list of values only,
[ v for k, v in mydict.items() if k >= 6 ]
[ mydict[k] for k in mydict.keys() if k >= 6 ]
map( mydict.get, filter( lambda k: k >= 6, mydict.keys() ) )
