Final answer:
The function return_subdictionary creates a new dictionary that contains only the key:value pairs from the original dictionary, where the values are even numbers.
Step-by-step explanation:
The given function, return_subdictionary, takes a dictionary as an argument and creates a new dictionary that only contains key:value pairs where the values are even numbers. To accomplish this, the function iterates over each key:value pair in the original dictionary using the items() method. It checks if the value is divisible by 2 using the modulo operator (%), and if so, adds the key:value pair to the new dictionary.
For example, if the original dictionary is {'a': 3, 'b': 4, 'c': 5, 'd': 6}, the function would return {'b': 4, 'd': 6}, since the values 4 and 6 are even numbers.
The new_dict dictionary is initialized as an empty dictionary at the beginning of the function. If no even numbers are found in the original dictionary, an empty dictionary is returned as specified.