Built-in Functions for Dictionaries

The len function also works for dictionaries but in this case it returns the number of key-value pairs.

>>>print len(translator)
10    

The in operator works on dictionaries and it tells you whether something appears as a key in the dictionary.

>>>'five' in translator 
True 
>>>'nine' in translator
True  
>>> 'ten' in translator
True 
>>> 'eleven' in translator
False

So far we’ve been working with keys, but if we want to work with values that is also possible. In order to see if the value appears in

>>>vals = translator.values()
>>>print 'cinque' in vals
True