# Creating a dictionary
student = {
    "name": "Alice",
    "age": 21,
    "major": "AI"
}

# Accessing values by key
print(student["name"])  # Output: Alice

# Using get() method to safely access values
print(student.get("grade", "Not Found"))  # Output: Not Found

# Modifying values
student["age"] = 22

# Adding new key-value pairs
student["grade"] = "A"

# Removing a key-value pair
student.pop("major")  # Removes "major" entry

# Looping through dictionary
for key, value in student.items():
    print(key, ":", value)

# Dictionary keys, values, and items
print(student.keys())    # Output: dict_keys(['name', 'age', 'grade'])
print(student.values())  # Output: dict_values(['Alice', 22, 'A'])
print(student.items())   # Output: dict_items([('name', 'Alice'), ('age', 22), ('grade', 'A')])

# Nested dictionary
record = {
    "id": 101,
    "info": {
        "name": "Bob",
        "department": "CSE"
    }
}
print(record["info"]["name"])  # Output: Bob