Python memoryview() built-in function
From the Python 3 documentation
Return a “memory view” object created from the given argument. See Memory Views for more information.
Introduction
The memoryview() function creates a memory view object from a given argument. A memory view allows you to access the memory of another object, like a <router-link to="/builtin/bytes">bytes</router-link> or <router-link to="/builtin/bytearray">bytearray</router-link> object, without making a copy. This is highly efficient for large data, as it avoids memory duplication.
Examples
Here’s how you can use memoryview():
# Create a bytearray
data = bytearray(b'hello world')
# Create a memory view of the data
view = memoryview(data)
# Access the data through the view
print(view[0]) # Output: 104 (ASCII for 'h')
print(view[6:11]) # Output: <memory at ...> (a slice of the memory)
print(view[6:11].tobytes()) # Output: b'world'
# You can also modify the underlying data through the view
view[0] = 72 # ASCII for 'H'
print(data) # Output: bytearray(b'Hello world')