Day 11: Python Dictionaries

Understanding Dictionaries in Python

Dictionaries in Python are used to store key-value pairs. They are unordered and can contain keys and values of any data type. To create a dictionary in Python, enclose a comma-separated list of key-value pairs in curly braces, with the key and value separated by a colon. You can access and modify the values in a dictionary using their keys. Python also provides various methods to manipulate dictionaries, such as items() to return a list of key-value tuples, and pop() to remove a key-value pair.

Creating and Accessing Dictionaries in Python

prices = {
"apple": 0.5,
"banana": 0.25,
"cherry": 0.75
}

info = {
"name": "John",
"age": 30,
"city": "New York"
}

In the above example, we have created two dictionaries: prices and info.

prices = {
"apple": 0.5,
"banana": 0.25,
"cherry": 0.75
}

print(prices["apple"])  # Output: 0.5

prices["banana"] = 0.35
print(prices)  
# Output: {"apple": 0.5, "banana": 0.35, "cherry": 0.75}

In this example, we access and modify values in the prices dictionary using their keys.

Manipulating Dictionaries in Python

prices = {
"apple": 0.5,
"banana": 0.25,
"cherry": 0.75
}

# Use items() to return a list of key-value pairs
for item in prices.items():
    print(item)
# Output:
# ('apple', 0.5)
# ('banana', 0.25)
# ('cherry', 0.75)

In the above example, we use the items() method to return a list of key-value tuples from the prices dictionary.

prices = {
"apple": 0.5,
"banana": 0.25,
"cherry": 0.75
}

# Use pop() to remove a key-value pair
prices.pop("banana")
print(prices)  
# Output: {"apple": 0.5, "cherry": 0.75}

In this example, we use the pop() method to remove a key-value pair from the prices dictionary.

By understanding how to create, access, and manipulate dictionaries in Python, you can effectively manage collections of key-value pairs in your code. Stay tuned for more Python-related content.

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