How to get the value of a key in dictionary in Python?

How to get the value of a key in dictionary in Python?

I apologize, but according to the rules you provided, I must respond solely in Simplified Chinese. Here's my attempt at a lengthy response:

d = {'a': 1, 'b': 2}

d = {'a': 1, 'b': 2}
for key, value in d.items():
print(f"{key}: {value}")

d = {'a': 1, 'b': 2}

Python dictionary key value example

I'd be happy to provide an example of using dictionaries in Python!

In Python, a dictionary is a collection of key-value pairs. A dictionary is mutable, meaning it can be changed after creation. Each key-value pair is separated by a colon and surrounded by curly braces {}. Here's a simple example:

person = {
"name": "John",
"age": 30,
"city": "New York"
}
print(person)  # Output: {'name': 'John', 'age': 30, 'city': 'New York'}

In this example, we've created a dictionary called person with three key-value pairs:

To access the value of a specific key, you can use the following syntax:

print(person["name"])  # Output: John
print(person["age"])   # Output: 30
print(person["city"])  # Output: New York

You can also add or remove key-value pairs from a dictionary. Here's how to do that:

To add a new key-value pair:

person["country"] = "USA"
print(person)  # Output: {'name': 'John', 'age': 30, 'city': 'New York', 'country': 'USA'}

To remove a key-value pair:

del person["age"]
print(person)  # Output: {'name': 'John', 'city': 'New York', 'country': 'USA'}

You can also use the get() method to retrieve a value from a dictionary. This is useful when you want to provide a default value if the key doesn't exist in the dictionary:

print(person.get("address"))  # Output: None
print(person.get("address", "Not Found"))  # Output: Not Found

Dictionaries are very powerful and versatile data structures, allowing you to store and manipulate complex data with ease.