The update method of dictionary class

Method Name:

update

Method Signature:

update([another])

Overview:

Updates the dictionary from another dictionary or another iterable. In case of an iterable, it is to have one or more iterables containing name-value pairs.

Parameters:

A dictionary or an iterable containing iterables of name value pairs or keyword arguments of the form name1=value1, name2=value2..nameN=valueN

Return Value:

None

Example 1:

# Example Python program that updates
# the values present in a dictionary
# using another dictionary

d1 = {1:"a",
2:"b",
3:"c"};

d2 = {1:"z",
2:"y",
3:"x"};

print("d1 - Before update:");
print(d1);

d1.update(d2);

print("d1 - After update:");
print(d1);

Output:

d1 - Before update:
{1: 'a', 2: 'b', 3: 'c'}
d1 - After update:
{1: 'z', 2: 'y', 3: 'x'}

Example 2:

# An example Python program that updates
# dictionary keys with new values from
# a tuple of tuples

# Original dictionary
groceryToBuy = {"Maple Syrup"       :2,
               "Oatmeal"           :1,
               "White Bread"       :4,
               "Alfredo Sauce"       :1,
               "Marinara Sauce"   :2,
               "Cheddar Cheese"   :4,
               "Parmesan Cheese"   :4,
               "Mozzarella Cheese"   :3,
               "Chicken Broth"    :2,
               "Tomato Soup"        :2,
               "Sausage"            :8
               };

# Tuple of tuples to update certain keys in the
# Original dictionary
groceryUpdates = (("Mozzarella Cheese", 5),
("White Bread", 7),
);

groceryToBuy.update(groceryUpdates);
print("Dictionary after updating from a tuple of tuples:");
print(groceryToBuy);

Output:

Dictionary after updating from a tuple of tuples:
{'Maple Syrup': 2, 'Oatmeal': 1, 'White Bread': 7, 'Alfredo Sauce': 1, 'Marinara Sauce': 2, 'Cheddar Cheese': 4, 'Parmesan Cheese': 4, 'Mozzarella Cheese': 5, 'Chicken Broth': 2, 'Tomato Soup': 2, 'Sausage': 8}