d = {}
d.has_key(key_in) # if has the key of key_in
d.keys() # keys list
d.values() # values list
d.get(key_in,[defualt]) # it will return 'NoneType' or [default] if with the second argument, if dict has no key of key_in, it will raise error with d[key_in]
if d: # if d is empty, it will be False