Python:双括号做什么？

my_tuple = (1, 2, 3, 4, 5)

my_set = {1, 2, 3, 4, 5}

my_dict = {"key1": "value1", "key2": "value2"}

my_string = "Hello, {}!"
print(my_string.format("World"))

def my_function():
    print("Hello, World!")

my_string = "Hello"
my_string2 = "World"
my_string3 = my_string + " " + my_string2
print(my_string3)

my_list = [1, 2, 3]
my_squared_list = [x**2 for x in my_list]
print(my_squared_list)

def my_function(my_list):
    return [x**2 for x in my_list]

my_list = [1, 2, 3]
my_squared_list = my_function(my_list)
print(my_squared_list)