Assign variable in while loop condition in Python?

Question

I just came across this piece of code

while 1:
    line = data.readline()
    if not line:
        break
    #...

and thought, there must

Answer 1

Starting Python 3.8, and the introduction of assignment expressions (PEP 572) (:= operator), it's now possible to capture the condition value (data.readline()) of the while loop as a variable (line) in order to re-use it within the body of the loop:

while line := data.readline():
  do_smthg(line)