[Luyt]

A while ago, I was also sceptical about the walrus operator, although I use assignments in expressions all the time in C++. But when I was perusing a library written Python the other day, I found five spots in which the walrus operator would make sense - eliminating one line of source code without readability suffering from it.

[bakery2k]

Is saving 5 lines of code really worth breaking Python's "one way to do it" design principle?

[masklinn]

Python's principle is not an has never been "one way to do it". Python's principle is:

> There should be one — and preferably only one — obvious way to do it.

Which is a very, very different assertion. And there remains one — and exactly only one — obvious way to do an assignment, because the walrus operator is literally invalid syntax as a statement:

    >>> [a:=1]
    [1]
    >>> a:=1
      File "<stdin>", line 1
        a:=1
         ^
    SyntaxError: invalid syntax

[CallocRoast]

That principle was bullshit anyway. There have always been multiple ways to do things, the one way was just whatever the elder Pythonista deemed to be pythonic that day.

[dr_zoidberg]

In my work we have code in many places along the lines of:

    data = expensive_function(blah, blah_blah)
    if data:
        # many lines of processing
        data = expensive_function(blah, blah_bah)

And seen a lot of times where newcomers forget the assingment at the end that makes everything move. So yeah, the walrus version would be a lot simpler:

    while data := expensive_function(blah, blah_blah):
        # process data

This is just one of the "edge cases" where the walrus makes sense.

[pwdisswordfish2]

Yes. That principle was quite silly to begin with.