PYTHON

Python :=

#The walrus operator := assigns values to variables as part of a larger expression.
#In this example, the assignment expression helps avoid calling len() twice:

if (n := len(a)) > 10:
    print(f"List is too long ({n} elements, expected <= 10)")

:: python

>>> range(10)[::2]
[0, 2, 4, 6, 8]

seq[start:end:step]

python <>

a = 1
b = 2

if a != b:
 print("Dunno")

if a <> b:
 print("Dunno")


above mentioned code are same As described in the documentation, 
they are the same. <> is deprecated and was removed in Python 3, 
so you should use !=

https://docs.python.org/2/reference/expressions.html#not-in