Question

What is the difference between the dictionary methods pop and popitem?

Short answer

Answer: The main differences between the pop and popitem methods are: 1. The pop method requires a key as an argument, while popitem does not take any arguments. 2. The pop method removes and returns the value associated with the specified key, while popitem removes and returns the last key-value pair in the form of a tuple. 3. The pop method can handle non-existent keys by providing a default value, while popitem raises a KeyError if the dictionary is empty.

Step-by-step solution

Understanding pop method

The pop method is used to remove an item from the dictionary based on its key. The syntax for using the pop method is: dictionary.pop(key, default_value) where "key" is the key of the item we want to remove and "default_value" (optional) is the value to be returned if the specified key does not exist in the dictionary. The method will return the value associated with the key and remove the key-value pair from the dictionary. If the key does not exist and no default value is provided, the method will raise a KeyError.

Examples of pop method

Let's see some examples of how to use the pop method: dict1 = {'a': 1, 'b': 2, 'c': 3} # Removing item with key 'b' value = dict1.pop('b') # value will be 2, and dict1 will be {'a': 1, 'c': 3} # Trying to remove item with non-existent key 'd' and providing a default value value = dict1.pop('d', None) # value will be None, and dict1 remains unmodified # Trying to remove item with non-existent key 'd' without providing a default value # This will raise a KeyError: dict1.pop('d')

Understanding popitem method

The popitem method is used to remove and return the last item (key-value pair) from the dictionary. Its syntax is: dictionary.popitem() The method does not take any arguments and returns a tuple containing the key-value pair. If the dictionary is empty, the method will raise a KeyError.

Examples of popitem method

Let's see some examples of how to use the popitem method: dict1 = {'a': 1, 'b': 2, 'c': 3} # Removing and returning the last item item = dict1.popitem() # item will be ('c', 3), and dict1 will be {'a': 1, 'b': 2} # Using an empty dictionary dict2 = {} # Trying to remove and return the last item from an empty dictionary # This will raise a KeyError: dict2.popitem()

Differences between pop and popitem

The main differences between the pop and popitem methods are: 1. The pop method requires a key as an argument, whereas popitem does not take any arguments. 2. The pop method removes and returns the value associated with the specified key, while popitem removes and returns the last key-value pair in the form of a tuple. 3. The pop method can handle non-existent keys by providing a default value. In contrast, popitem always raises a KeyError if the dictionary is empty.