collection data types ( 'mars 'rover'venus - 'blue[ ' ' 'root none figure dictionary is an unsorted collection of (keyvalueitems with unique keys key items can also be removed (and returnedfrom the dictionary using the dict pop(method dictionaries support the built-in len(functionand for their keysfast membership testing with in and not in all the dictionary methods are listed in table because dictionaries have both keys and valueswe might want to iterate over dictionary by (keyvalueitemsby valuesor by keys for examplehere are two equivalent approaches to iterating by (keyvaluepairsfor item in items()print(item[ ]item[ ]for keyvalue in items()print(keyvalueiterating over dictionary' values is very similarfor value in values()print(valueto iterate over dictionary' keys we can use dict keys()or we can simply treat the dictionary as an iterable that iterates over its keysas these two equivalent code snippets illustratefor key in dprint(keyfor key in keys()print(keyif we want to change the values in dictionarythe idiom to use is to iterate over the keys and change the values using the brackets operator for examplehere is how we would increment every value in dictionary dassuming that all the values are numbersfor key in dd[key+